A Hummingbirds Guide to M.E. :: Information on Myalgic Encephalomyelitis

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What is M.E.?

M.E: The Medical Facts

The M.E. Symptom List

The M.E. Ability Scale

The Terminology Explained

Activism and Advocacy

Smoke and Mirrors

The Myths about M.E.

A Million Stories Untold

The M.E. symptom list

The Ultra-comprehensive Myalgic Encephalomyelitis Symptom List. Most symptom lists are based on the bogus 'fatigue' model and so leave out all the neurological, cardiac, cardiovascular, immune system and other symptoms which truly define the illness. This is a comprehensive M.E. symptom list based on research by the world's leading M.E. experts.

This page features the full-length version of the text.

A summarised (2 page) version of this text is also available, see: The M.E. Symptom Summary

See the Downloads section below to download this paper in Word or PDF format.

The M.E. symptom list: Introduction

It is important that the scientific facts of Myalgic Encephalomyelitis (M.E.), including an accurate general idea of the symptomatology of the illness, become widely known by the media and the wider medical community, as well as the friends and families of sufferers and the public at large.

There is also a real need for more of this type of information to be available to the M.E. community. Despite the abundance of good research available dating back to the 1950s (and earlier), most people with M.E. today – thanks to the financially and politically motivated creation of the bogus disease category of ‘CFS’ in the 1980s – have little or no information about the various neurological, cognitive, cardiac, cardiovascular, immunological, muscular and gastrointestinal (and other) symptoms which characterise M.E. So many of these very ill people are just desperate for what amounts to basic information about their symptoms and their illness.

Just to know that there are other people with M.E. who sometimes (or every day) wake up completely paralysed because of sleep paralysis, have heart-attack like cardiac episodes, seizures, or suffer with black outs and severe problems with memory and that it's not just you (for example), can really be an enormous relief in itself – even if there may be no actual treatment for the symptom as yet. Knowledge is power and a comprehensive M.E. symptom list is a simply vital tool for every person with Myalgic Encephalomyelitis.

The ultra-comprehensive Myalgic Encephalomyelitis symptom list has been compiled using references produced by the world’s leading M.E. experts.

More experienced and more knowledgeable M.E. experts than these – Dr Byron Hyde MD. and Dr. Elizabeth Dowsett MD. in particular – simply DO NOT EXIST.

The symptom list is divided into three categories:

Section 1: The facts about M.E. (and the myths about M.E.)
Section 2: Descriptions of individual symptoms of M.E.
Section 3: On the pattern/cause of symptom exacerbations, relapses and disease progression in M.E.

Before reading the list, please note:

This text is NOT a diagnostic tool and should not be used as such.

It should not be assumed that because you may have some of the symptoms on the list that you necessarily have M.E. - many of them are common in a variety of other disorders and it is the pattern of symptoms which enables a M.E. diagnosis to be made, as well as the presence of a number of core characteristics and symptoms which are always present in the illness, and without which a diagnosis of M.E. should never be made. (For example, damage to the brain, the CNS, which is visible on brain scans, and so on.) Even having a large number or percentage of the symptoms on this list does NOT necessarily mean a M.E. diagnosis is likely or even a possibility. See: Testing for M.E. for more information on the diagnosis of M.E.

Also note that if you find a symptom of yours listed here it does NOT mean that you don't still have to tell your doctor about it and get it checked out. 'Just' because it's a M.E. symptom it does not mean it can't be serious. Cardiac problems in particular should always be investigated, as should lymph node pain (among many others). Also, never assume that every symptom you have is 'just' M.E., having M.E. does not mean you are immune from developing other illnesses as well unfortunately. Make sure you get every new symptom checked by your doctor.

The symptoms are listed in no particular order, and of course, remember that nobody will get every symptom. Also note that this is not a pure symptom list and some additional information (signs of the illness, causes of some of the symptoms, recent research findings etc.) has also been included. Also note that this list does not contain any additional anecdotal symptoms.

Note: To read a description of the symptoms of M.E. which combines the available research with a personal description of the illness, and which describes more than 50 symptoms of the illness in detail, see the new paper: What it feels like to have Myalgic Encephalomyelitis: A personal M.E. symptom list and description of M.E.

A brief overview: What is M.E.?

Because of the vast amount of inaccurate information being propagated about Myalgic Encephalomyelitis by various vested interest groups (helped immeasurably by the creation of the bogus disease category of ‘CFS’ as well as a number of vague and misleading umbrella terms such as ‘ME/CFS’ ‘CFS/ME’ ‘CFIDS’ and Myalgic ‘Encephalopathy’ etc.) it is important to explain briefly what are the myths about M.E., and the symptoms of M.E.

Myalgic Encephalomyelitis is not synonymous with being tired all the time. If a person is very fatigued for an extended period of time this does not mean they are having a ‘bout’ of M.E. To suggest such a thing is no less absurd than to say that prolonged fatigue means a person is having a ‘bout’ of multiple sclerosis, Parkinson’s disease or Lupus. If a person is constantly fatigued this should not be taken to mean that they have M.E. no matter how severe or prolonged their fatigue is. Fatigue is a symptom of many different illnesses as well as a feature of normal everyday life – but it is not a defining symptom of M.E., nor even an essential symptom of M.E.

There are a number of post-viral fatigue states or fatigue syndromes which may follow common infections such as mononucleosis/glandular fever, hepatitis, Q fever, Ross river virus and so on. M.E. is an entirely different condition to these self-limiting fatigue syndromes however (and is not caused by the Epstein Barr virus or any of the herpes or hepatitis viruses), the science is very clear on this point. People suffering with any of these post-viral fatigue states or fatigue syndromes do not have M.E. M.E. is also not the same condition as Lyme disease, athletes over-training syndrome, burnout, depression, somatisation disorder, candida, multiple chemical sensitivity syndrome or Fibromyalgia, or indeed any other illness. M.E. is a distinct neurological illness with a distinct; onset, symptoms, aetiology, pathology, response to treatment, long and short term prognosis – and World Health Organization classification (G.93.3) (Hyde 2006, 2007, [Online]) (Hooper 2006, [Online]) (Hooper & Marshall 2005, [Online]) (Hyde 2003, [Online]) (Dowsett 2001, [Online]) (Hooper et al. 2001, [Online]) (Dowsett 2000, [Online]) (Dowsett 1999a, 1999b, [Online]) (Dowsett 1996, p. 167) (Dowsett et al. 1990, pp. 285-291) (Dowsett n.d.a, [Online]).

M.E. is also not defined by ‘fatigue following exertion which can last up to 24 hours’ as the bogus definitions of ‘CFS’ describe. Fatigue following activity (or post-exertional fatigue or malaise) is a common symptom of a large number of different illnesses – but what is happening in M.E. is quite different. Overexertion does not cause fatigue in M.E. but instead a worsening of the severity of the illness generally and of various neurological, cognitive, cardiac, cardiovascular, immunological, muscular and gastrointestinal (and other) symptoms. The severity of these symptoms can range from mild to severe to life-threatening. The effects of overexertion can last for hours, days, weeks or even many months in M.E., or can even be permanent. The onset of these post-exertional effects are very often significantly delayed so that very often the worsening of the illness caused by overexertion has not even begun within 24 hours in M.E., let alone been completely resolved in that time. The reaction people with M.E. have to physical and mental activity, sensory input and orthostatic stress not only has nothing to do with mere fatigue (or ‘malaise’) but is in fact unique to M.E. in a number of ways. This reaction is so abnormal in fact that exercise testing is one of the series of tests which can be used to help confirm a M.E. diagnosis, as are various tests which measure the abnormal responses to orthostatic stress seen in M.E. This is simply not the case in post-viral fatigue syndromes, Lyme disease, Fibromyalgia and so on. These patient groups do not exhibit the same measurable pathological abnormalities as M.E. patients in these (and other) tests. Recent research has also shown that postural stress exacerbates cardiac insufficiency in M.E. and that this cardiac insufficiency is the cause of many of the symptoms and much of the disability of M.E. This pathology is also not seen in any of those illnesses causing fatigue after exertion which are commonly misdiagnosed as ‘CFS.’ The way people with M.E. respond to physical activity and orthostatic stress (etc.) is profoundly different than in these other illnesses; it is an entirely different problem, of a much greater magnitude (Cheney 2006, [video recording]) (Hooper & Marshall 2005, [Online]) (Hyde 2003, [Online]) (Dowsett 2001, [Online]) (Hooper et al. 2001, [Online]) (Dowsett 2000, [Online]) (Dowsett 1999a, 1999b, [Online]) (Dowsett et al. 1990, pp. 285-291) (Ramsay 1986, [Online]).

What defines M.E. is not ‘chronic fatigue’ but a specific type of acquired damage to the brain. Myalgic encephalomyelitis is an acutely acquired illness initiated by a virus infection with multi system involvement which is characterised by post encephalitic damage to the brain stem; a nerve centre through which many spinal nerve tracts connect with higher centres in the brain in order to control all vital bodily functions – this is always damaged in M.E. (Hence the name Myalgic Encephalomyelitis.) Central nervous system (CNS) dysfunction, and in particular, inconsistent CNS dysfunction is undoubtedly both the chief cause of disability in M.E. and the most critical in the definition of the entire disease process.

Myalgic Encephalomyelitis is a loss of the ability of the CNS (the brain) to adequately receive, interpret, store and recover information which enables it to control vital body functions (cognitive, hormonal, cardiovascular, autonomic and sensory nerve communication, digestive, visual auditory balance etc). It is a loss of normal internal homeostasis. The individual can no longer function systemically within normal limits. This dysfunction also results in the inability of the CNS to consistently programme and achieve normal smooth end organ response. There is also multi-system involvement of cardiac and skeletal muscle, liver, lymphoid and endocrine organs. Some individuals also have damage to skeletal and heart muscle.

This diffuse brain injury is initiated by a virus infection which targets the brain; M.E. represents a major attack on the central nervous system (CNS) by the chronic effects of a viral infection. M.E. is an infectious and primarily neurological disease process which occurs in epidemic and sporadic forms. There is a history of recorded outbreaks of M.E. going back to 1934, when an epidemic of what seemed at first to be poliomyelitis was reported in Los Angeles. A review of M.E. outbreaks found that clinical symptoms were consistent in over sixty recorded epidemics of M.E. spread all over the world. M.E. has been linked to Poliomyelitis (Polio) since 1934 and for a number of years M.E. was referred to as ‘atypical Polio.’ A significant number of the world’s leading M.E. experts believe that M.E., like Polio, is caused by an enterovirus. The evidence which exists to support this theory is compelling, for example: M.E. epidemics very often followed Polio epidemics, M.E. resembles Polio at onset, serological studies have shown that communities affected by an outbreak of M.E. were effectively blocked (or immune) from the effects of a subsequent polio outbreak, evidence of enteroviral infection has been found in the brain tissue of M.E. patients at autopsy, and so on. (See: The outbreaks of M.E. and for more information.)

M.E. is primarily neurological, but because the brain controls all vital bodily functions virtually every bodily system can be affected by M.E. Again, although M.E. is primarily neurological it is also known that the vascular and cardiac dysfunctions seen in M.E. are also the cause of many of the symptoms and much of the disability associated with M.E. – and that the well-documented mitochondrial abnormalities present in M.E. significantly contribute to both of these pathologies. There is also multi-system involvement of cardiac and skeletal muscle, liver, lymphoid and endocrine organs in M.E. Some individuals also have damage to skeletal and heart muscle. Thus Myalgic Encephalomyelitis symptoms are manifested by virtually all bodily systems including: cognitive, cardiac, cardiovascular, immunological, endocrinological, respiratory, hormonal, gastrointestinal and musculo-skeletal dysfunctions and damage.

M.E. is an infectious neurological disease and represents a major attack on the central nervous system (CNS) – and an associated injury of the immune system – by the chronic effects of a viral infection. There is also transient and/or permanent damage to many other organs and bodily systems (and so on) in M.E. M.E. affects the body systemically. Even minor levels of physical and cognitive activity, sensory input and orthostatic stress beyond a M.E. patient’s individual post-illness limits causes a worsening of the severity of the illness (and of symptoms) which can persist for days, weeks or months or longer. In addition to the risk of relapse, repeated or severe overexertion can also cause permanent damage (eg. to the heart), disease progression and/or death in M.E.

M.E. is not stable from one hour, day, week or month to the next. It is the combination of the chronicity, the dysfunctions, and the instability, the lack of dependability of these functions, that creates the high level of disability in M.E. (It is also worth noting that of the CNS dysfunctions, cognitive dysfunction is one of the most disabling characteristics of M.E.)

At first glance a list of M.E. symptoms it may seem that every symptom possible is mentioned, but the seemingly random list of symptoms in fact form unique and distinct patterns – they are anything but ‘random’ for those with knowledge of the illness and/or of how the illness effects the body’s various systems. Different people have a lot of different symptoms but the general pattern and evolution of major symptoms are remarkably coherent from patient to patient in M.E.; they fit a precise pattern that is nearly identical from one patient to the next.

There is just no other illness that is even remotely like M.E. M.E. is a distinct, recognisable disease entity which contrary to popular belief is not difficult to diagnose and can in fact be diagnosed relatively early in the course of the disease (within just a few weeks) – providing that the physician has some experience with the illness. (The usual case of M.E. is so distinct that people with M.E. can recognise fellow sufferers almost in an instant.) Although there is (as yet) no single test which can be used to diagnose M.E. there are a series of tests which can confirm a suspected M.E. diagnosis. If all tests are normal, if specific abnormalities are not seen on certain of these tests (eg. brain scans), then a diagnosis of M.E. cannot be correct (Hyde 2006, 2007, [Online]) (Hooper 2006, [Online]) (Hooper & Marshall 2005, [Online]) (Hyde 2003, [Online]) (Dowsett 2001, [Online]) (Hooper et al. 2001, [Online]) (Dowsett 2000, [Online]) (Dowsett 1999a, 1999b, [Online]) (Hyde 1992 p. xi) (Hyde & Jain 1992 pp. 38 - 43) (Hyde et al. 1992, pp. 25-37) (Dowsett et al. 1990, pp. 285-291) (Ramsay 1986, [Online]) (Dowsett n.d.a, [Online]) (Dowsett & Ramsay n.d., pp. 81-84) (Richardson n.d., pp. 85-92). (See Testing for Myalgic Encephalomyelitis for more information.)

All of this is not simply theory, but is based upon an enormous body of clinical information which has been published in prestigious peer-reviewed journals all over the world and spans over 60 years. Confirmation of this hypothesis is supported by electrical tests of muscle and of brain function (including the subsequent development of PET and SPECT scans) and by biochemical and hormonal assays. Newer scientific evidence is increasingly strengthening this hypothesis. Myalgic Encephalomyelitis is neither ‘mysterious’ nor ‘medically unexplained. Many aspects of the pathophysiology of the disease have, indeed, been medically explained in volumes of research articles. These are well-documented, scientifically sound explanations for why patients are bedridden, profoundly intellectually impaired, unable to maintain an upright posture and so on.

Myalgic Encephalomyelitis is a debilitating illness which has been recognised by the World Health Organisation (WHO) since 1969 as an organic neurological disorder. M.E. is similar in a number of significant ways to illnesses such as multiple sclerosis, Lupus and Polio. M.E. affects all races and socio-economic groups and has been diagnosed all over the world with a similar strike rate to multiple sclerosis. Children as young as five can get M.E., as well as adults of all ages. M.E. can be extremely disabling, and is not a self-limiting or short term illness. 25% of M.E. sufferers are severely affected and housebound and bedbound. In some cases Myalgic Encephalomyelitis can also be progressive, or fatal. Governments around the world are currently spending $0 a year on M.E. research (Hyde 2006, 2007, [Online]) (Hooper 2006, [Online]) (Cheney 2006, [video recording]) (Hyde 2003, [Online]) (Hooper 2003, [Online]) (Dowsett 2001, [Online]) (Hooper et al. 2001, [Online]) (Dowsett 2000, [Online]) (Dowsett 1999a, 1999b, [Online]) (Hyde 1992 p. xi) (Hyde & Jain 1992 pp. 38 - 43).

M.E. is an infectious neurological illness of extraordinarily incapacitating dimensions that affects virtually every bodily system – not a problem of medically unexplained ‘chronic fatigue.’

For more information about the medical and political facts of M.E. see: Putting Research and Articles into Context, The misdiagnosis of CFS, Smoke and mirrors and What is Myalgic Encephalomyelitis?
Note that many different illnesses may share a percentage of the individual neurological, gastrointestinal or cognitive features of M.E., (and so on) but there is no other illness which encompasses each of the specific neurological, cognitive, immunological, gastrointestinal, cardiac and cardiovascular, endocrinological, respiratory, hormonal and other features and symptoms which make up M.E. This specific combination of symptoms/pathology is not seen in any other illness. There are also a number of characteristics of M.E. which are unique to the illness. The acute onset of M.E. also sets it apart from many other illnesses commonly associated with a gradual onset, as do many other characteristics. See: The misdiagnosis of CFS for more information.
What is CFS? CFS was created in a response to an outbreak of what was unmistakably M.E., but this new name and definition did not describe the known signs, symptoms, history and pathology of M.E. It described a disease process that did not, and could not exist. All each of these flawed CFS definitions ‘define’ is a heterogeneous (mixed) population of people with various misdiagnosed psychiatric and miscellaneous non-psychiatric states which have little in common but the symptom of fatigue (a symptom seen in many illnesses but not a defining feature of M.E. nor even an essential symptom of M.E.). The disease category ‘CFS’ has undoubtedly been used to impose a false psychiatric paradigm of M.E. by allying it with various unrelated psychiatric fatigue states and post-viral fatigue syndromes (etc) for the benefit of various (proven) financial and political interests.

CFS and M.E. are NOT the same, and M.E. and CFS are not synonymous terms. Every diagnosis of ‘CFS’ based on any of the ‘CFS’ definitions is a misdiagnosis. For more information on this topic, including how the ‘CFS’ scam also negatively affects the media, doctors and the public etc., see: The misdiagnosis of CFS, Smoke and mirrors and Why the disease category of ‘CFS’ must be abandoned. The truth about the organic and distinct neurological illness M.E. must not be allowed to be buried under cover of ‘fatigue’ and ‘CFS’ for another 20 years!

Descriptions of individual symptoms of M.E.

This list has been compiled using the highest quality resources available from the world’s leading M.E. experts, each of whom have been studying M.E. for more than 20 years and have each seen thousands of individual patients. (With the exception of the book by Verrillo and Gellman which combines the research into M.E. by these same experts with the findings of a large number of M.E. case studies.) The sources for this list are:

‘The Clinical and Scientific Basis of Myalgic Encephalomyelitis’ edited by Dr Byron Hyde M.D.
Papers on Myalgic Encephalomyelitis by Dr Byron Hyde M.D.
Papers on Myalgic Encephalomyelitis by Dr Melvin Ramsay M.D.
Papers on Myalgic Encephalomyelitis by Dr Elizabeth Dowsett M.D.
Papers/lectures by Dr Paul Cheney M.D.
‘The Doctor's Guide to CFIDS’ by Dr. David S. Bell M.D.
‘CFIDS - A Treatment Guide’ by Erica F. Verrillo and Lauren M. Gellman

(Note that while some of these authors have unfortunately used the terminology of’ CFS’ or ‘CFIDS’ it is undoubtedly the neurological illness M.E. that has been described in each of these books and articles etc.) Symptoms are not presented as direct quotes from these sources, and are instead paraphrased, to aid readability.

Sections: CARDIAC & CARDIOVASCULAR DYSFUNCTIONS; COGNITIVE & NEUROLOGICAL DYSFUNCTIONS; DIGESTIVE DYSFUNCTIONS; ENDOCRINE & NEUROENDOCRINE DYSFUNCTIONS; EXERCISE, EXERTION & PHYSICAL ACTIVITY; HEADACHES; HEARING, VESTIBULAR & SPEECH PROBLEMS; HYPOGLYCEMIA; IMMUNE SYSTEM DYSFUNCTIONS; JOINT DYSFUNCTIONS; MUSCLE DYSFUNCTIONS; ORAL DYSFUNCTIONS; PAIN; REPRODUCTIVE DYSFUNCTIONS; RESPIRATORY DYSFUNCTIONS; SEIZURES & SEIZURE ACTIVITY; SKIN, HAIR & NAILS; SLEEP DYSFUNCTIONS; URINARY TRACT DYSFUNCTIONS; VISUAL DYSFUNCTIONS; WEATHER SENSITIVITY; WEIGHT CHANGES; M.E. FATALITIES and CO-MORBID ENTITIES.

CARDIAC & CARDIOVASCULAR DYSFUNCTIONS

Reduced maximum heart rate and/or an elevated resting heart rate

Extreme pallor (usually just before or during a relapse)

Odema (swelling of the hands and feet)

Neurally Mediated Hypotension (NMH) low blood pressure (which causes the blood to pool in the extremities) this occurs due to an abnormal reflex interaction between the heart and the brain. This can also occur with Delayed Postural Hypotension (usually delays are around 10 minutes).

Postural Orthostatic Tachycardia Syndrome - POTS (a heart rate increase of 30 bpm or more from the supine to the standing position within ten minutes or less) which can also occur with Delayed Postural Orthostatic Tachycardia Syndrome (usually delays are around 10 minutes)

Orthostatic light-headedness and/or fainting or black outs

Very low blood pressure (hypotension) on reclining, or high blood pressure on activity. Sudden low blood pressure may cause blackouts.

Tachycardia and an exacerbation of symptoms on orthostatic challenge (maintaining an upright posture) beyond certain limits. Lying down markedly improves symptoms for M.E. patients. See section 3 for more information

Sensations of chest pain, chest pressure or fluttering sensations in the mid-chest, palpitations (skipped heart beats), tachycardia (rapid heart beat – may be 170bpm or higher), premature atrial and ventricular contractions (early or extra heartbeats), various arrhythmias (abnormal heart rhythms), ectopic heart beats (a contraction of the heart that occurs out of its normal rhythmic pattern, it may feel like a thumping sensation in the chest) and sleep bradycardia (a slowing of the heart rate above what is expected with sleep) can all occur.

COGNITIVE & NEUROLOGICAL DYSFUNCTIONS

A worsening of symptoms (including cognitive function) with cognitive exertion beyond a certain level. See section 3 for more information

Problems with memory including; difficulty making and consolidating new memories (particularly short-term memories), difficulty recalling formed memories and difficulties with visual recall and with immediate and delayed verbal recall are common. Short-term memory problems may lead to people forgetting where they are or what they are doing, this can be so severe that patients are unable to finish a sentence. Facial agnosia may also occur (not being able to recognise faces, even those of close friends and family)

Multi-tasking problems, an inability to learn to perform new tasks, forgetting how to perform routine tasks and a difficulty with simultaneous processing. There can be a difficulty with following step-by-step instructions, recipes or performing any tasks which require a series of separate actions. Sequencing dysfunction can also occur; inability to look words up in a dictionary, to look up phone numbers in a phone book or to organise files etc. Patients may also need extra sensory cues to complete tasks (for example, the patient may need to be able to see what they are doing to be able to complete a task where formerly the task could be completed using touch alone eg. turning on a light or operating the controls in a car)

Cognitive slowing (tasks can take much longer than usual)

Impairment of concentration; maintaining a reasonable level of concentration on a task for even a short period of time may become extremely difficult, or impossible. There is a need for mental micro-rests.

Difficulty with visual and aural comprehension; difficulty following oral or written directions, trouble distinguishing figure from ground and speech comprehension difficulties. Greater difficulty with auditory comprehension than visual is common.

Word, letter and short term ordering problems, for example; transposition - reversal of letters or numbers, words or sentences when speaking or writing (pseudodyslexia)

Inability to locate the words for writing (Agraphia). Handwriting may also change completely with the onset of illness, may be deformed in a way consistent with brain damage (this may wax and wane with the severity of the illness)

Problems with reading (Alexia) or word blindness; patient can still read but what is read is not comprehended and cannot be compared with known information already stored. If reading is still possible, text may have to read many times before it can be comprehended.

Difficulty or an inability to understand speech (Wernicke's Aphasia); words are heard clearly, they are not garbled, but they make no sense. It is a loss of the ability to interpret normal language. When the input is aural, there seems to be a loss of the initial orienting information. The person is actively listening, but the information simply does not register at all or must be repeated several times before it registers.

Increased need for visual cues in understanding speech; visual or multisensoral cues are an important compensatory tool in M.E. (for example, a patient may not be able to understand the same conversation with the same person on the telephone that they understood perfectly well when conducted face-to-face).

In speaking, important elements are often left out of the sentence such as the verb or subject, sometimes the syntax is askew. At times speech makes no sense and/or does not relate to the question asked. Sometimes speech comprehension is delayed which can result in long pauses, interruptions, mistiming of responses and apparent non sequiturs. Patients themselves may or not be aware of these problems with their speech. Incorrect word selection (paraphasia) is common, such as using the wrong word from the right category or using a word that sounds similar to the correct word but has a different meaning. Commonly used words become hard to retrieve. These problems combined may result in a significant loss of communicative ability. There can also be a difficulty pronouncing words intelligibly (Dysarthria) or a complete inability to express language (Broca's Aphasia).

Dyscalculia; (loss of arithmetic skills) an inability or difficulty to do simple additions and other calculations, to count money, add up columns etc (irrespective of the quality of former mathematical abilities) is common. There may also be a difficulty or confusion with following timetables or keeping scheduled appointments.

Loss of verbal and performance intelligence quotient (IQ) (A 20 point loss is average, although for some people the loss is far more profound)

A loss the ability to block out extraneous and unwanted information and noise; M.E. patients lose of the ability to distinguish noise from required information and tend to shut down all intake after minimal prolongation of the information signal. For example, a person may not be able to understand speech when there is more than one person speaking, more than one conversation taking place, or when there is a TV or radio on in the background. (This receptive shutdown has alarming connotations for making memories and can also at times create real danger to the M.E. patient)

An exaggerated response to even small amounts of additional input or stimulus (light, noise, movement, vibration) is common, causing incoming messages to become scrambled or blurred resulting in distorted signals and odd sensations (ie. low level seizure activity). Even very low levels of light or noise etc. can also cause an exacerbation of other symptoms, or of the severity of the illness generally. See section 3 for more information

Polyneuropathy; a neurological problem that occurs when many peripheral nerves throughout the body malfunction simultaneously. Many polyneuropathies have both motor and sensory involvement and some have autonomic dysfunction. Hyperreflexia; overactive or overresponsive reflexes eg. twitching or spastic tendencies as well as the lessening or loss of control ordinarily exerted by higher brain centres of lower neural pathways (disinhibition).

Perceptual and sensory dysfunctions eg, spatial instability and disorientation. There may be a loss of co-ordination or clumsiness - difficulty in judging distance, placement and relative velocity (caused by proprioception dysfunctions, proprioception being the perception of stimuli relating to your own position, posture, equilibrium, or internal condition) Extension or quick rotation of the neck can cause dizziness (also due to proprioception dysfunctions)

Altered time perception (losing time), feeling 'spaced out' or 'cloudy' or not quite real somehow

Disorders of colour perception - recognising colours but forgetting what they mean, (Seeing the red light at an intersection, knowing it is red, but not recognising that red means ‘stop,’ for example)

Abstract reasoning dysfunction; difficulty organising, integrating, and evaluating information to form conclusions or make decisions (some patients find it almost impossible to make decisions)

Stroke-like episodes

Short periods of amnesia may occur which may be associated with disorientation where the patient momentarily does not know where or who she is which may cause considerable anxiety. Some patients lose large parts of the day but this is infrequent. In most cases the patient can be brought out of the amnesiac attack with cues

In severe illness patients can become unconscious, comatose for up to 23, 24 hours a day (the brain becomes unable to maintain wakefulness). There can be a difficulty in maintaining full consciousness for more than a few seconds, minutes, or half-hour periods at a time.

Volitional problems; difficulty starting or stopping tasks, or switching from one task to another (a neurological dysfunction where the body does not respond appropriately, or quickly, or without difficulty, to the minds commands; is related to sleep paralysis. This is a central dysfunction and may be similar to that seen in Parkinsonianism)

A feeling of agitated exhaustion is common (neurological in origin)

Emotional symptoms include: mood swings (emotional lability) – crying easily, excessive irritability etc or intense emotions such as rage, terror, overwhelming grief, anxiety, depression and guilt. Sometimes there can be an emotional flattening or situations may be erroneously interpreted as novel (due to prefrontal cortex dysfunction). Disinhibition may occur to varying levels. Anxiety and panic attacks may occur, often not tied to environmental triggers. Emotional symptoms in M.E. tend to be linked to exacerbations in physical symptoms, there are often not environmental triggers. (Also note that injuries to the areas or centres of the brain which control emotions are of an identical nature as those that affect physical function; these emotional symptoms are an organic part of the illness caused by anatomical and physiological damage to the brain just as nystagmus, seizures or any other neurological problems or symptoms are. These emotional changes are also due in part to the cognitive changes caused by M.E., for example the problems with memory.)

DIGESTIVE DYSFUNCTIONS

Oesophageal spasms (felt as extreme pain in the centre of the chest that sometimes radiates to the chest or mid-back) or oesophageal reflux (heartburn)

Difficulty swallowing (or an inability to swallow)

Great thirst, increased appetite, food cravings or lack of appetite

Inability to tolerate much fat in the diet (gallbladder problems)

Changes in taste and smell; an increased sense of smell or bizarre smells. Strange taste in mouth (bitter, metallic)

Multiple new food allergies and intolerances

Bloating, abdominal pain, nausea, indigestion or vomiting is common, as is diarrhoea, constipation or an alternation between the two.

Intense gallbladder pain (in the upper right quadrant of the abdomen) or liver pain, tenderness or discomfort. Liver problems (along with other problems) can lead to a ‘poisoned’ feeling.

Alcohol intolerance is common (ranging from mild to a total intolerance)

ENDOCRINE & NEUROENDOCRINE DYSFUNCTIONS

Thyroid; thyroid pain, inflammation or dysfunction (usually secondary hypothyroidism). Adrenal gland dysfunction; aspects of both overactive and underactive adrenal function or pituitary dysfunctions

Loss of thermostatic stability - suddenly feeling cold in warm weather, recurrent feelings of feverishness or chills or hot flashes particularly involving the upper body. Feeling cold and shivering one minute and hot and sweating the next is common. A low-grade fever may occur following exertion

Subnormal body temperature and marked diurnal fluctuation (temperature fluctuation throughout the day)

Cold hands and feet, sometimes on only one side

Sweating episodes (profuse sweating, sometimes even when cold) - with the sweat often having quite a sour smell. Night sweats and spontaneous day sweats may occur

Swelling of the extremities or eyelids

Loss of adaptability and worsening of symptoms with stress (due to endocrine dysfunctions etc.)

EXERTION & PHYSICAL ACTIVITY

An exacerbation of symptoms with physical activity beyond a person’s individual limits, and a worsening of the illness generally (etc.) with continued overexertion. See section 3 for more information.

A sudden unexpected feeling of being 'high' can occur (due to neurological dysfunctions) leading to (usually short) bouts of physical hyperactivity

Severe muscle weakness (paresis) or paralysis. Muscles will often function normally to start with, but pain and weakness (or paralysis) develop after short periods of use and then take 3, 4 or 5 days (or longer) to resolve (normal muscle recovery is around 200 minutes). Problems arise from sustained muscle use - it is a pathologically slow or impaired recovery of muscle after exercise. (It is a problem involving the metabolism of the muscles). Thus a patient may be easily able (for short periods) to lift something moderately heavy one or two times, but be unable to lift something very light many times (such as a soup spoon for example). This muscle weakness/paralysis affects all muscles/organs, including the heart, eyes and brain.

Impaired cognitive processing, a reduced maximum heart rate, a drop in body temperature or dyspnea (shortness of breath) with overexertion. See section 3 for more information

Loss of the natural antidepressant effect of exercise

Inappropriate signs of immune system activation can be brought on by overexertion (ie. flu-like symptoms)

See also the CARDIAC & CARDIOVASCULAR DYSFUNCTIONS section.

HEADACHES

Onset of a new type, severity or pattern of headaches is common. See also the PAIN section

A feeling of extreme pressure felt at the base of the skull and/or severe pain or sensation of pressure behind the eyes (or ears). Sinus, pressure or tension headaches (dull continual headaches which are not actually caused by anxiety as the name may suggest) can occur, as can hypoglycaemia headaches (generalised prickly ache over the top of the head)

HEARING, VESTIBULAR & SPEECH DYSFUNCTIONS

Hyperacusis - an intolerance to normal sound volume and range (but particularly sounds in the higher frequencies). Sudden loud noises can also cause a startle response (flushing and a rapid heartbeat) and there can also be an extreme intolerance to vibration or movement.

Excessive sensory inputs (noise, vibration) may lead to low level seizures and exacerbations of other symptoms . See section 3 for more information

Tinnitus - ringing, buzzing, humming, clicking, popping and squeaking noises generated in the ear

Hearing loss - sound can be muffled or indistinct or sound strangely flat, there can be a loss of tone perception

Sharp transient ear pain, deep itching in the ears and/or swelling of the nasal passages

Dizziness or vertigo - a sensation that your surroundings (or you) are spinning wildly (can cause vomiting). Vertigo may also be expressed in a milder form as an inability to watch TV or to read.

Acute profound ataxia (balance problems) or a sensitivity to motion/movement (which can affect balance)

Nystagmus - a rapid involuntary oscillation of the eyeballs

The voice may become very weak, hoarse or fall to a whisper, and then there can be total loss of speech. There may also be a slowed rate of speech, sometimes with stammering, stuttering, muddled or slurred speech or difficulty moving the tongue to speak or getting enough air to speak more than a few words at a time.

See also the COGNITIVE & NEUROLOGICAL DYSFUNCTIONS section for more information about difficulties with speech in M.E.

HYPOGLYCEMIA

Hypoglycaemia or hypoglycaemia-like symptoms (problems with blood sugar regulation/low blood sugar)

IMMUNE SYSTEM DYSFUNCTIONS

Lymphadenopathy: lymph nodes which are tender to the touch and painful on movement. The lymph nodes in the front and back of the neck, armpits, elbows and groin are most frequently affected, particularly on the left side.

Recurrent flu-like symptoms (general malaise, fever and chills, sweats, cough, night sweats, low grade fever, sore throat, feeling hot often and low body temperature)

Very severe throat pain, scratchiness and tenderness which often worsens with exercise, exertion or before relapses. Throat may also feel clogged and require constant clearing. Throat may appear red or have characteristic ‘crimson crescents’ around the tonsillar membranes of the upper throat

An increased susceptibility to secondary infections can be a significant problem. In addition to seasonal colds and flu patients are also more susceptible to upper respiratory tract or urinary tract infections, topical fungal infections and recurring shingles. All of these infections also last longer, can be more severe and occur more frequently and may also cause relapses either concurrently or just after the initial infection. This is true even in cases where prior immunity has been established. See section 3 for more information.

In some patients there is instead a decreased susceptibility to secondary infections. There is a tendency to catch either every virus going around or to ‘never catch anything’ depending on whether the immune system is under- or over-active (which changes dependant on which stage of the illness the person is in). Starting to get colds and flu’s again can be a sign of M.E. remission or improvement

Reactions to chemical smells: chemical sensitivities may occur to indoor and outdoor chemical air contaminants; perfumes, hairsprays, gasoline, household cleaning products, plastic and glue out-gassing. Can produce allergic reactions although not all chemical sensitivities are IgE mediated. May also cause an exacerbation of other symptoms. See section 3 for more information

New sensitivities may also occur to some drugs and medications (particularly those which act on the CNS)

Worsening of existing allergies and/or new severe sensitivities/allergies/intolerances to many varieties of food (and food additives) and to airborne allergens: pollen, mould, animal dander, fur and feathers or dust.

Allergy symptoms:

Skin: pallor, itching, burning, tingling, flushing, warmth or coldness, sweating behind the neck, hives, blisters, blotches, red spots, pimples, dermatitis, eczema
Eyes: blurred vision, itching, pain, watering, eyelid twitching, redness of inner angle of lower lid, drooping or swollen eyelids
Ears: earache, recurring ear infections, dizziness, tinnitus, imbalance
Nose: nasal discharge or congestion sneezing
Mouth: dry mouth, increased salivation, stinging tongue, itching palate, toothache
Throat: tickling or clearing, difficulty swallowing
Lungs: shortness of breath, air hunger, wheezing, cough, mucous or recurrent bronchial infections
Heart: pounding or skipped heartbeats, chest tightness
Gastrointestinal tract: burping, heartburn, indigestion, nausea, vomiting, abdominal pain, gas, cramping, diarrhoea, constipation, mucus in stool; frequent, urgent or painful urination, bedwetting (in children)
Muscular system: muscle fatigue, weakness, pain, stiffness, soreness
Central nervous system: headache, migraine, vertigo, drowsiness, sluggishness, giddiness
Cognition: lack of concentration, feeling of 'separateness', forgetting words or names, anxiety, tension, panic, overactivity, restlessness, jitteriness, depression, PMS

JOINT DYSFUNCTIONS

Significant myalgia (pain) in joints is often widespread. The most common joints affected are knees, ankles, elbows, hips but pain in the fingers also occurs. Aching in the joints is also common

Gelling (stiffness) in the joints that develops after holding a position for awhile, usually sitting or upon awakening but can also be caused by changes in temperature or humidity

Gait abnormalities and a difficulty with tandem gait

MUSCLE DYSFUCNTIONS

Significant myalgia in muscles is often widespread (sharp, shooting, burning or aching pain). Pain can be extremely severe in M.E. See also the PAIN section

Transient tingling, numbness and/or burning sensations (or other odd sensations) in the face or extremities (paresthisias).

There is sometimes atrophy of specific muscle groups (a shrinking in size visible to the eye)

Inability to form facial expressions leading to a ‘slack’ facial appearance

A loss of the ability to chew or swallow

Severe muscle weakness (paresis) or paralysis. Muscles will often function normally to start with, but pain and weakness (or paralysis) develop acutely after short periods of use and then take 3, 4 or 5 days (or longer) to resolve (normal muscle recovery is around 200 minutes). Problems arise from sustained muscle use - it is a pathologically slow or impaired recovery of muscle after exercise. (It is a problem involving the metabolism of the muscles). Thus a patient may be easily able (for short periods) to lift something moderately heavy one or two times, but be unable to lift something very light many times (such as a soup spoon for example). This muscle weakness/paralysis affects all muscles/organs, including the heart, eyes and brain.

Visible tremors and twitches of the muscles (involuntary movements)

Muscle spasms, which can be extremely severe and painful. There may be spasms of the hands and feet which can lead to ‘clawed’ deformities or spasms in the neck which cause the head to twist to one side

Slight hesitation in movement or ‘cogwheel’ effect with movement

ORAL DYSFUNCTIONS

Dental decay and periodontal disease (gum disease) are much more common than in the general population

Frequent canker sores (painful sores in the mouth which look like small bumps with white heads)

Loose teeth and endodontal (the soft tissue in the centre of the tooth) problems

Temperature sensitivity in the teeth and/or pain in the teeth

PAIN

Three different types of muscle pain in M.E.:

Patient complains of feeling as though they have been beaten repeatedly with an axe handle; bruised and hurt all over. Is sometimes associated with a dull headache and an inability to concentrate.
Severe spike-like pain, usually in the main muscle mass in the leg; extensors or flexors. It is commonly described as feeling as though a nail or a knife had been stuck into the area.
Occurs after a particular muscle group has been in use for an extended period; the affected muscles become weak/paralysed and painful and this takes 3-5 days (or longer) to resolve. The affected muscle can frequently be palpated and is hard and swollen.

Cephalgias and other head area pain: encephalitic pain, pain behind the eyes, expanding head pain, ear pain, opthalmic pain, tooth-hypersensitivity pain, spike-like pain, fibromyalgia pain, formification, sore throat and spasm associated pain

Other types of pain: chest and abdominal pain, causalgia and other neuralgic pain, abdominal pain, urogenital pain, pain in the extremities (hypothallamic dysfunction pain, periarthritic pain, bone pain and muscle pain)

Pain reception impairment: skin is very sensitive to the touch and there can be also be allodynia - a pain response to stimuli not usually painful (some patients find the weight of their sheets becomes extremely painful and intolerable for example)

REPRODUCTIVE DYSFUNCTIONS

Menstrual cycles may become shorter, longer or irregular. Periods may also become lighter or disappear altogether (usually when illness is severe) There may also be an intensification of M.E. symptoms before and during a period

Lowered libido

Impotence

RESPIRATORY DYSFUNCTIONS

Erratic breathing pattern

Dyspnea - air hunger or difficulty breathing (often on waking or with exertion), which can be severe. See section 3 for more information

Persistent coughing and wheezing

SEIZURES & SEIZURE ACTIVITY

Grand mal seizures (where there is loss of consciousness and motor dysfunctions),

Petit Mal seizures - absence seizures (where you are conscious but unaware of your actions. A person may continue with an activity as though asleep – an ambulatory automatism may occur)

Simple partial seizures - do not involve loss of consciousness but produce altered sensations, perception, mood or bodily sensations; somatosensory seizures, autonomic seizures, focal motor seizures, auditory seizures, visual seizures. Complex partial seizures: episodic dysphasia/dyspagia (incomprehension of speech and inability to speak), olifactory hallucinations. Other seizures: tremulous attacks and psychomotor attacks. (Dr Byron Hyde M.D. states in his M.E. textbook that; by definition all M.E. patients will have some level of seizure activity as part of their illness.)

Sensory storms/overload phenomena or a worsening of symptoms generally caused by a hypersensitivity to light, sound, vibration, movement, temperature, odours and/or mixed sensory modalities. See section 3 for more information

Myoclonus (strong involuntary jerks of the arms, legs or entire body)

SKIN, HAIR & NAILS

Skin: extreme pallor, rashes, dry and peeling skin, acne, spontaneous bruising, fungal infections, butterfly rash on face, flushing of face, fingerpads may be atrophic so that the fingerprints are hard to see, skin may become red and shiny (generally after long-term illness). This is sometimes referred to as a ‘destruction of fingerprints.’.

Hair: hair loss and poor quality regrowth.

Nails: vertical ridges, bluish nail bed, brittleness, fungal infections

SLEEP DYSFUNCTIONS

Unrefreshing sleep (waking up feeling worse than when you went to bed)

Disrupted, chaotic or reversed circadian (sleep and wake cycle) rhythms

Difficulty initiating sleep, maintaining sleep (fragmented sleep) or hyposomnia (lack of sleep) may occur

Hypersomnia - excessive sleeping (common in the acute stages of the illness, a rare feature thereafter. Is more common in children than adults and thought to be most often caused by a dysfunction in the posterior hypothalamus and the upper part of the mid-brain.)

Very light sleep (lack of deep stage sleep)

Dreaming changes: intensely colourful and bright dreams (vivid), violent and attacking nature of dreams (nightmares), frequency of hypnagogic and hypnapagogic dream states (waking dreams, thematic dreams, pain dreams and sleep paralysis) and increased dreaming activity (thought to be caused by sensory seizures in the midbrain). There is also sometimes a complete lack of dreams.

Sleep paralysis: temporary paralysis after sleeping (also called waking paralysis, can last from minutes to hours), early waking states (where you are neither asleep nor awake which can last for minutes or many hours) or dysania can occur

Night extremity hypothermia

URINARY TRACT DYSFUNCTIONS

Urinary frequency and bladder dysfunction, uncomfortable or painful/burning urination (Dysuria), difficulty passing urine, incontinence and/or nocturia (excessive urinating at night)

VISUAL DYSFUNCTIONS

External visual dysfunctions: photophobia (extreme sensitivity to light), oscillating or diminished pupillary accommodation responses with retention of reaction to light, nystagmus (a rapid involuntary oscillation of the eyeballs), painful or burning sensations in the eyes, floaters, spots and scratchiness in vision, tearing and dry eye, internal and external ophthalmoplegia (paralysis of the extraocular muscles which are responsible for eye movements) changes in colour vision, sluggish focus, an inability to focus or accommodation difficulty (difficulty switching from one focus to another) can all occur as can double, tunnel, wavy or blurred vision, or night blindness.

Central visual dysfunctions: visual comprehension dysfunction, reading ability loss or difficulty, writing ability loss or difficulty, distance or spatial dysfunction, loss of depth of field – less ability to make figure/ground distinctions, vision reversals and vision clouding. See also the COGNITIVE & NEUROLOGICAL DYSFUNCTIONS section for more on difficulties with reading and writing

WEATHER SENSITIVITY

Intolerance of extremes of hot and cold weather, may cause an onset of the homeostatic disequilibrium symptom complex. Periods of extended hot weather in particular are seldom well tolerated by M.E. patients.

Insomnia, migraines, irritability or generally ‘feeling off’ a day or two before the weather changes. Changes in temperature or humidity can cause stiffness or increased aching or pain in the muscles. Changes in barometric pressure can cause night sweats and spontaneous sweating during the day

WEIGHT CHANGES

Marked weight gain (often independent of dietary changes)

Marked weight loss (often independent of dietary changes). Rapid weight loss can also occur despite large quantities of food being eaten. (Weight loss independent of dietary changes seems to be more common amongst younger sufferers, particularly children and teenagers.)

M.E. FATALITIES:

Most deaths from M.E. (around two thirds) are due to organ failure, usually cardiac or pancreatic. Death can also occur as a result of secondary infections or problems with maintaining breathing. See THE LATE EFFECTS OF ME by Dr Elizabeth Dowsett for more information. See also: The Severity of M.E. and M.E. Fatalities.

CO-MORBID ENTITIES: (Note that some conditions, such as NMH for example, are instead included in the general symptoms list because they are so central to M.E.)

Increased tendency for Mitral Valve Prolapse, especially in children (breathlessness, fatigue, edema)

Viral myocarditis - inflammation of the heart (usually of little consequence but which can sometimes lead to substantial cardiac damage and severe acute heart failure. It can also evolve into the progressive syndrome of chronic heart failure. There have been sudden deaths associated with exceptional physical exertion in patients with viral illnesses)

Pericarditis (the outer layer of the heart, pericardium, is inflamed. Symptoms include chest pain, shortness of breath, and rapid, shallow respiration)

Secondary or reactive depression (as with any other debilitating chronic illness)

Irritable Bowel Syndrome

Raynauds phenomenon (poor circulation)

Shingles

Systemic yeast/fungal infections

Multiple Chemical Sensitivity Syndrome MCSS

Carpal tunnel syndrome (weakness, pain, and disturbances of sensation in the hand)

Pyriform muscle syndrome causing sciatica

Positive Fibromyalgia tender points (FMS) and Myofascial trigger points (MPS) are common

Temporomandibular Joint Syndrome TMJ (spasms of the jaw muscles causing intense pain)

Hashimoto's thyroiditis

Sicca Syndrome

Endometriosis (the presence and growth of functioning endometrial tissue in places other than the uterus that often results in severe pain and infertility) may be more common in M.E.

Dysmenorrhoea - menstrual pain experienced a week before, during and a few days after periods (other symptoms include; headache, suprapubic cramping, backache, pain radiating down to anterior thigh, nausea and vomiting, diarrhea, syncope)

More severe or new onset PMS

Migraines (nausea, vomiting, head pain, light and noise sensitivity which can last for hours or days)

Restless Legs Syndrome RLS

Sleep apnea

Irritable Bladder Syndrome

Cystitis (inflammation of the urinary bladder)

Prostatitis (inflammation of the prostate gland)

Sjogrens syndrome (autoimmune disorder affecting moisture producing glands in the body)

On the pattern of symptoms and relapses etc.

What characterises M.E. every bit as much as the individual neurological, cognitive, cardiac, cardiovascular, immunological, endocrinological, respiratory, hormonal, muscular, gastrointestinal and other symptoms is the way in which people with M.E. respond to physical and cognitive activity, sensory input and orthostatic stress, and so on. In other words, the pattern of symptom exacerbations, relapses and of disease progression.

The way the bodies of people with M.E. react to these activities/stimuli post-illness is unique in a number of ways. Along with a specific type of damage to the brain (the central nervous system) this characteristic is one of the defining features of the illness which must be present for a correct diagnosis of M.E. to be made. The main characteristics of the pattern of symptom exacerbations, relapses and disease progression (and so on) in Myalgic Encephalomyelitis include:

A. People with M.E. are unable to maintain their pre-illness activity levels. This is an acute change; M.E. patients can only achieve 50%, or less, of their pre-illness activity levels post-M.E.

Only being able to achieve 50% or less of your pre-illness activity level immediately upon becoming ill is very common – if not universal – in Myalgic Encephalomyelitis. (Although a small percentage of sufferers may possibly be somewhat less severely affected at onset.) This is not a gradual change in ability levels which occurs over weeks, months or years; it is an acute change. The onset of M.E. is frequently very dramatic, M.E. patients can very often tell you not just the day that they became ill, but the exact hour they became ill.

M.E. can commonly be diagnosed within just a few weeks if the doctor has experience with M.E. (If all tests are normal, M.E cannot be the correct diagnosis.) See: Testing for M.E. for more information. For more information on the viral infection evident at onset in people with M.E., and the outbreaks of M.E. etc. see: The outbreaks (and infectious nature) of M.E.
M.E. is an acute onset illness, however it should be noted that: (a) some sufferers will be unsure of their onset type (they may not recall it, or may not recall it accurately, for various reasons) and (b) in some cases, acute onset M.E. is preceded by a series of unrelated minor infectious episodes (in a previously well patient) which may be misinterpreted as being a gradual onset of the M.E. (These minor infectious episodes may be due to the immune system being under temporary or chronic stress from events such as; recent immunisation, repetitive contact with a large number of infectious persons, or the effect of travel; as in exposure to a new subset of virulent infections. This pre-existing temporary or chronic immune system weakness is not seen in all patients and is not what causes M.E., although a compromised immune system will of course make the body more vulnerable to all types of infections, including M.E.)

B. People with M.E. are limited in how physically active they can be but they are also limited in similar way with; cognitive exertion, sensory input and orthostatic stress.

The bodies of people with Myalgic Encephalomyelitis respond inappropriately to anything that forces the body to have to react in some way or work harder in some way, in order to maintain internal homeostasis, including (but not limited to): physical activity, cognitive exertion (including emotional stress), sensory input and orthostatic stress. It should also not be assumed that a person with M.E. will necessarily react more severely to (or have greater limits on) physical activity than with cognitive exertion, sensory input or orthostatic stress. Some patients find that their most severe relapses come from orthostatic stress, while others will have to be more careful with their levels of sensory input or cognitive exertion as compared to physical activity. Other patients may be equally limited with each of these activities or stimuli, and so on. It varies from patient to patient and can also change over the course of the illness.

What is Homeostasis? Homeostasis is the property of a living organism, to regulate its internal environment to maintain a stable, constant condition, by means of multiple dynamic equilibrium adjustments, controlled by interrelated regulation mechanisms. Homeostasis is one of the fundamental characteristics of living things. It is the maintenance of the internal environment within tolerable limits. M.E. causes a loss of the ability of the CNS (the brain) to adequately receive, interpret, store and recover information which enables it to control vital body functions. There is a loss of normal internal homeostasis; the individual can no longer function systemically within normal limits. (Metabolic problems also contribute to this inability to maintain homeostasis.)
Physical activity in this context does not just mean aerobic exercise; it includes any physical movement or activity, including stretching and even very small movements. Cognitive activity refers to any type of thinking, or mental processing. Sensory input includes exposure to light, noise and movement etc. Orthostatic stress or postural stress includes sitting or standing, but also things like having a few pillows under your head when lying down or sitting up in bed; orthostatic stress is caused by any posture other than lying down flat (perhaps with legs raised to reduce the load on the heart; unless the patient is wearing pressure socks, which achieve the same purpose.).

C. When a person with M.E. is active beyond their individual (physical, cognitive, sensory or orthostatic) limits this causes a worsening of various neurological, cognitive, cardiac, cardiovascular, immunological, endocrinological, respiratory, hormonal, muscular, gastrointestinal and other symptoms.

When a person with M.E. is active beyond their individual post-illness limits, the result is not tiredness, fatigue or even exhaustion – nor is ‘malaise’ an accurate word to describe what occurs. There simply is no one symptom caused by overexertion in M.E. What does happen is that there is a worsening of all sorts of different symptoms and of the severity of the illness generally with overexertion. (Repeated or severe overexertion can also cause disease progression, permanent damage (eg. to the heart), or death in M.E.) It is an entirely different problem of a much greater magnitude.

Overexertion causes an exacerbation of all sorts of combinations of neurological, cognitive, cardiac, cardiovascular, immunological, endocrinological, respiratory, hormonal, muscular, gastrointestinal and other symptoms which can be mild, moderate, severe, or even life threatening (eg. seizures and cardiac events). Many of the symptoms involved are present at a lower level at rest, but overexertion causes them to worsen. (Although some patients may also have some symptoms that only appear after overexertion.)

The types of symptoms produced in response to certain levels of physical activity, cognitive activity, sensory stimuli or orthostatic stress may or may not vary depending on the type (and severity) of the activity or stimuli involved. But very often the types of symptoms worsened or produced by overexertion are fairly similar regardless of which exertion or input was involved. Overexertion can sometimes cause just one or two symptoms to worsen (eg. cardiac problems) but often a large cluster of symptoms are worsened. The cluster of symptoms made worse by excessive exertion or stimulus is often very similar from patient to patient, as generally it is a worsening of the most common symptoms of the illness. Patients commonly experience a combination of the following symptoms:

Profound cognitive dysfunctions (and various other neurological disturbances), muscle weakness (or paralysis), burning eye pain or burning skin, subnormal temperature or low-grade fever, sore throat or painful lymph nodes (and/or other signs of inappropriate immune system activation), faintness, weakness or vertigo, loss of co-ordination, dyspnea, an explosion of sensory phenomena (low level seizure activity), cardiac and/or blood pressure disturbances, facial pallor and/or a slack facial expression, widespread severe pain, nausea or feeling as if ‘poisoned,’ feeling cold and shivering one minute and hot and sweating the next, anxiety or even terror (as an organic part of the attack itself rather than as a reaction to it) and hypoglycaemia. Often the patient will feel an urgent need to retreat from all homeostatic pressures. The types of symptoms triggered vary widely from patient to patient, but some combination of these is common. There may also be an accompanying exacerbation of other symptoms. These symptoms often combine to create an indescribable and overwhelming experience of terrible illness that is unique to M.E, and can be profoundly incapacitating. At its most severe, the patient feels as if they are about to die.

Each of the symptoms caused or exacerbated by overexertion can be clearly articulated without difficulty whether they be; seizures, cardiac events, labile blood pressure, tachycardia, shortness of breath, muscle pain, muscle weakness or muscle paralysis, facial paralysis, black outs, flu-like symptoms, nausea, inability to speak or to understand speech, problems with memory, and so on. It makes no scientific or logical sense to subsume these very specific symptoms, and very specific and varied combinations of symptoms, under a vague and inaccurate label of mere ‘fatigue.’ To say that all of these very different and very specific – and in some cases very serious – symptoms can be accurately summarised as being a problem of mere ‘fatigue,’ ‘malaise’ or ‘exhaustion’ is absurd.

A large number of illnesses cause significant fatigue or malaise after activity (for example post-mononucleosis or glandular fever fatigue syndromes, Lyme disease and Fibromyalgia and so on) but what is happening in M.E. is simply not the same; the symptomatology and pathology – and the effect of physical, cognitive and orthostatic overexertion on long-term prognosis – is very different in M.E.
Also note that: repeated or severe overexertion can also cause disease progression, permanent damage (eg. to the heart), or death in M.E. patients. Again, to suggest that these very serious and long-term effects – and fatalities – could be accurately summarised as being a problem of mere ‘fatigue’ is clearly absurd
An additional note on ‘fatigue’: The diagnosis of M.E. is determined upon the presence of certain neurological, cognitive, cardiac, cardiovascular, immunological,, muscular, gastrointestinal and other symptoms and characteristics (and so on) – the presence or absence of mere ‘fatigue’ is irrelevant. In addition to these other (far more serious) symptoms, some M.E. sufferers may also suffer with mild, moderate or severe fatigue some of the time, while others will not. Thus the symptom of fatigue is not an essential symptom of M.E. and does not define M.E. (Although the symptom of fatigue is essential to qualify for a misdiagnosis of ‘CFS’). For more information see: M.E. is not defined by 'fatigue' and The misdiagnosis of CFS

D. The level of physical activity, cognitive exertion, sensory input or orthostatic stress needed to cause a significant or severe worsening of symptoms varies from patient to patient, but is often trivial compared to a patient’s pre-illness tolerances and abilities.

When there is talk of ‘overexertion’ leading to an exacerbation of symptoms in M.E. what is being referred to is not hard exercise, it is not anything resembling what healthy people would recognise as ‘overexertion.’ This term just refers to any activity which goes beyond a person’s individual post-M.E. limits.

There is a lot of variation from patient to patient but very often the levels of activity required to cause relapse are trivial compared to a patient’s pre-illness tolerances and abilities. For example, what constitutes overexertion for someone with severe M.E. could be something as small as rolling over in bed, walking or talking for a few minutes, or eating a meal. The severity and duration of relapses varies depending on the severity of a person’s illness, but relapses in M.E. are very often way out of all proportion to the actual activity. Relapses can be very severe and prolonged (or even permanent) even if a person with M.E. has only gone past their individual limits in a seemingly minor way.

A note on M.E. and other illnesses: This extreme and out of all proportion reaction to even trivial levels of activity is just not seen in those illnesses causing fatigue (and other symptoms) after exertion which may commonly be misdiagnosed as ‘CFS.’ People with post-viral fatigue syndromes, Fibromyalgia and Lyme disease etc. are not affected by small activities for many weeks, months, or permanently, in this way. While people with M.E. and people with these other illnesses may all not improve with a graded exercise regime, the way people with M.E. respond to physical and cognitive activity, sensory input and orthostatic stress is profoundly different than in these other illnesses. The two problems are quite distinct.

E. The severity of M.E. waxes and wanes throughout the hour/day/week and month.

You can probably observe people with some illnesses carefully for an hour or so and collect a lot of good information about what they can and can’t do, how severe their illness is, and what their usual symptoms are from day to day, and so on. But M.E. is not one of those illnesses. Observing your average M.E. sufferer for an hour – or even a week or more – will not give an accurate indication of their usual daily activity level because the severity of M.E. waxes and wanes throughout the hour/day/week and month and people with M.E. can sometimes operate significantly above their usual illness level for short periods of time thanks to surges of adrenaline – albeit at the cost of severe and prolonged worsening of the illness afterward.

The severity of M.E. is not stable over the course of a day, or even from one hour (or even one minute) to the next: it also isn’t stable from one week or month to the next. This waxing and waning of the severity of the illness can be very unpredictable. The severity of M.E. also waxes and wanes from one minute/hour/day/week etc. due to the acute and delayed effects of overexertion.

Because of the lack of stability in M.E. you simply cannot know a M.E. sufferers usual ability level or severity level unless you have observed them over a very long period of time, or actually asked the person detailed questions about what their average daily activity limits, abilities and symptoms are. Just observing someone with M.E. do a certain task should not be taken to mean; (a) that they can necessarily repeat the task anytime soon, (b) that they would have been able to do it at any other time of day, (c) that they can do the same task every hour, day or even every week, or month, or (d) that they wont be made very ill afterwards for a considerable period because they had to really push themselves (and make themselves ill) to do the task. Most importantly, because the worsening of the illness caused by overexertion very often does not even begin until 48 or more hour afterwards you also can’t tell by looking if a particular activity was so far beyond a M.E. patient’s individual limits that they will end up having made themselves severely or permanently more ill by completing the task.

What is an adrenaline surge? Adrenaline is often referred to as the ‘fight or flight’ hormone as it kicks into action in situations of potential danger. Adrenaline also kicks in when the body is in physiological difficulty however, which is what is happening with M.E. sufferers very often. Adrenaline surges make the heart pump faster and raise your blood pressure, forcing blood around the body with greater force to supply the muscles with more oxygen, so that they can make a greater effort. (This is also associated with a diversion of blood away from certain areas of your brain and internal organs and into your muscles – so although your body is more capable your ability to think in complex ways can sometimes be lessened). Surges of adrenaline increase your metabolism, they also relax and dilate the airways so that we can take in more oxygen than usual. Adrenaline surges can also decrease the amount of pain you feel. As a result of all of these factors, adrenaline surges – while they last – have the ability to increase your physical speed, strength and other physical abilities. (Unfortunately, when these bursts of adrenaline wear off – as they must – people with M.E. are left far more ill afterwards as a result for many days, weeks, months or even years. For every short term ‘gain’ there is a far greater loss overall.)
A note on M.E. and other illnesses: This is another one of the characteristics which clearly differentiates authentic M.E. from various self-limiting post-viral fatigue syndromes and so on – the striking variability of symptoms not only in the course of a day but often within the hour. As many M.E. experts have noted, this variability of the intensity of the symptoms is simply not found in post-viral fatigue states or syndromes (etc).
There is also a waxing and waning of the physical signs of M.E. throughout the day, as Dr Hyde M.D. and Dr Jain M.D. explain, "A patient examined in the morning might have nystagmus, which would disappear at midday, recur later, disappear later and recur the next day."

F. The worsening of the illness caused by overexertion can be acute, but often does not reach its peak until 24 - 48 hours (or more) later.

Another reason that short-term and superficial judgements of ability and disability levels in people with M.E. are ill-advised and often very misleading – and are in fact almost guaranteed to give a falsely more optimistic view of daily ability levels – is because the relapses caused by exertion very often do not appear until 48 or more hours afterward, when the average observer is long gone.

The onset of the worsening of symptoms caused by overexertion is sometimes be acute but often will not peak until 48 hours or more afterward (this is particularly true with regard to physical, cognitive and orthostatic exertions). Symptoms will then persist for hours, weeks or many months, or longer. For many M.E. sufferers, the effects from significant overexertion will very often peak on day three.

Sometimes there is a significant worsening of symptoms evident at the time of overexertion. At other times, there may only be a minor worsening of symptoms at the time of overexertion, but the delayed effects will be severe. Sometimes the acute effects and the delayed effects will both be severe. It varies depending on the type and severity of the overexertion involved etc.

A note on M.E. and other illnesses: The ‘CFS’ definitions state that post-exertional symptoms ‘may take up to 24 hours to resolve.’ But to say that this is true of M.E. patients betrays an ignorance of the most basic facts of M.E. Post-exertional symptoms very often take far longer than 24 hours to even APPEAR in people with M.E., let alone be completely resolved in that time. These symptoms can take days, weeks, months or even several years to resolve. Overexertion can also cause a worsening of the base level of illness in M.E. and so the effects of overexertion can also be semi-permanent or permanent. Death can also occur due to overexertion in M.E. This significant delay in the onset of post-exertional symptoms is not seen in those illnesses causing fatigue (etc.) after exertion. Nor do the effects of even minor overexertion very often last for weeks, months, years or permanently in people with these various fatigue syndromes as they do with M.E. sufferers. There is also not the same risk of overexertion leading to death in these other illnesses, as there is with M.E (The cardiac insufficiency seen in M.E., which causes much of the symptomatology and the limits with activity and orthostatic stress and so on in M.E., is simply not seen in these other illnesses.)

G. If people with M.E. push past their individual limits too deeply or too often, the effects of overexertion can also accumulate over longer periods of time and lead to disease progression, or death.

In addition to the effects of overexertion commonly being delayed by 48 hours or so, the worsening of symptoms caused by overexertion can also sometimes be delayed (and accumulate) over weeks or even many months at a time until they are realised in a ‘crash.’ This is a period of intense worsening of the overall condition followed by a gradual return to the patient’s base level of illness over weeks, months or even years.

When the body is confronted with activity (or inputs) beyond the patient’s individual limits severely and/or repeatedly over time, these effects can also become cumulative in the long term; the patient becomes unable to return to their base level of illness at all. What this means is that long-term or permanent worsening of the overall severity of the condition is caused. Thus some patients are still dealing with the severe physical effects of inappropriate advice to exercise or to be more physically or mentally active etc. five, ten, fifteen or more YEARS afterward and for some patients the damage caused is permanent. Overexertion has also resulted in death in some cases of M.E.

Strong evidence exists to show that overexertion can have extremely harmful effects on M.E. patients. Patient accounts of leaving exercise programs much more severely ill than when they began them; wheelchair-bound or bed-bound or needing intensive care or cardiac care units, are common. (Recent research has shown that postural stress and physical and mental overexertion exacerbate cardiac insufficiency in this disease; see the notes below for more information.) In addition to the risk of relapse, permanent damage, and disease progression, there have also been reports of sudden deaths in M.E. patients following exercise. As M.E. expert Dr. Elizabeth Dowsett explains, ‘20% have progressive and frequently undiagnosed degeneration of cardiac muscle which has led to sudden death following exercise. Prompt recognition and advice to avoid over-exertion is mandatory.’

Recent research shows that mitochondrial dysfunction (etc.) leads to diastolic dysfunction and reduced stroke volume/low cardiac output in M.E. – and that certain levels of orthostatic stress and physical and mental activity etc. exacerbate this cardiac insufficiency. Dr Cheney explained recently that because it takes more metabolic energy for the heart to relax and fill with blood than it does for it to squeeze and pump blood, the hearts of people with M.E. don’t fill with the proper amount of blood before they pump which is what causes the reduced cardiac output and many of the symptoms of M.E. (and much of the disability of M.E.) So the tachycardia – fast heart rate – often seen in M.E. in response to orthostatic stress and so on is actually compensating for low stroke volume to help increase cardiac output. The heart doesn’t fill with enough blood before each beat of the heart so it is forced to beat faster to try to make up some of the shortfall, but people with M.E. are still left with reduced cardiac output leaves them very ill and disabled. If this problem is severe enough it can also result in death. As one M.E. advocate explains: ‘Cardiac output is sometimes too low to meet the demands of movement, and any attempt to exert oneself beyond one's own capacity for cardiac output - that is when demand exceeds cardiac capacity - would indeed result in death. Studies on dogs have shown that when the demands of the body exceed cardiac outp