The Hummingbirds' Foundation for M.E.

The Hummingbirds' Foundation for M.E. (HFME) is fighting for the recognition of M.E.,
and for patients to be accorded the same basic human rights as those with similar
disabling and potentially fatal neurological diseases such as M.S.

M.E. symptoms (in brief)

M.E. is primarily neurological, but also involves cognitive, cardiac, cardiovascular, immunological, endocrinological, metabolic, respiratory, hormonal, gastrointestinal and musculo-skeletal dysfunctions and damage. M.E. affects all vital bodily systems and causes an inability to maintain bodily homeostasis. More than 64 individual symptoms of M.E. have been scientifically documented.

M.E. symptoms

What defines M.E. is a specific type of viral damage to the brain.

M.E. represents a major attack on the CNS by the chronic effects of a viral infection which targets the brain: an enterovirus. The onset of M.E. is acute or sudden. More than 60 symptoms have been authentically documented in M.E.

M.E. is associated with signs and symptoms including (but not limited to):

Neurological signs and symptoms:

  • Inconsistent central nervous system function
  • Vertigo, disequilibrium and proprioception difficulties (e.g. lack of sense of 'up' and 'down' with eyes closed)
  • Temperature dysregulation and poor tolerance for hot or cold environments
  • Hyperacusis (sensitivity to noise) and photophobia (pain/relapse on exposure to light)
  • Pain and pressure at the back of the head (where the head meets the neck) and behind the eyes
  • Blurred vision, blacked-out vision, nystagmus, wavy visual field, and other visual disturbances
  • Stroke-like or coma-like episodes
  • Seizures and 'sensory storms' (while conscious)
  • Sleep paralysis, fragmented sleep, difficulty initiating sleep, lack of deep-stage sleep and/or a disrupted circadian rhythm
  • Many other varied neurological symptoms and abnormalities

Vascular and cardiovascular signs and symptoms:

  • A very high heart rate, chest pressure, heart pain and a fluttering/straining heart
  • Very low blood pressure particularly when upright (e.g. 84/48 or less in an adult at rest), orthostatic tachycardia/POTS and reduced circulating blood volume (up to 50%)
  • Feet burning painfully and turning blue/purple on standing (Reynaud's phenomenon)
  • Pain/discomfort/poor digestion following meals

Muscular signs and symptoms:

  • Muscle weakness and paralysis (affecting all muscles including the heart, eyes, digestive system etc.)
  • Muscle pain, twitching and uncontrollable spasms
  • Difficulty breathing and air-hunger, difficulty swallowing/chewing
  • Paresthesias, polyneuropathy or myoclonus

Cognitive signs and symptoms:

  • Word-finding difficulty, scanning or disjointed speech, speech reversals, difficulty or an inability to speak
  • Difficulty comprehending speech or delayed speech comprehension
  • Handwriting changes, difficulty writing or comprehending text
  • Difficulty with even basic mathematics (dyscalculia)
  • Difficulty with simultaneous processing, concentration, spatial perception and with sequencing
  • Difficulty making new memories, recalling formed memories and with immediate and delayed visual and verbal recall (e.g. facial agnosia). There is often a marked loss in verbal and performance IQ

Other signs and symptoms:

  • Nausea, vomiting and feeling 'poisoned' and very ill
  • Throat and gland pain/tenderness, chills and low grade fevers
  • Food allergies, alcohol intolerance, hypoglycaemia and sensitivity to common drugs/chemicals
  • Ghastly pallor of face with frequent lupus-like submaxillary mask or facial vasculoid rash
  • Parkinsonian rigidity of facial expression


What characterises M.E. every bit as much as the individual symptoms is the way in which people with M.E. respond to physical and cognitive activity, sensory input and orthostatic stress, and so on. It is unique in a number of ways and must be present for a correct diagnosis of M.E. to be made, and includes the following:

  1. People with M.E. are unable to maintain their pre-illness activity levels. This is an acute, sudden change. M.E. patients can only achieve 50% or less of their pre-illness activity levels.
  2. People with M.E. are limited in how physically active they can be but are also limited in similar ways with cognitive exertion, sensory input and orthostatic stress.
  3. When a person with M.E. is active beyond their individual limits, there is a worsening of various neurological, cognitive, cardiac, cardiovascular, immunological, endocrinological, respiratory, hormonal, muscular, gastrointestinal and other symptoms.
  4. The level of physical activity, cognitive exertion, sensory input or orthostatic stress (being upright) that is needed to cause significant relapse varies from patient to patient, but is often trivial compared to pre-illness tolerances and abilities.
  5. The severity of M.E. waxes and wanes throughout the hour/day/week and month.
  6. The worsening of the illness caused by overexertion often does not peak until 24 - 72 hours or more later.
  7. The effects of overexertion can accumulate over time and lead to disease progression or death.
  8. The activity limits of M.E. are not short term: an increase in activity levels beyond a patient's individual limits, even if gradual, causes relapse, disease progression or death.
  9. The symptoms of M.E. do not resolve with rest. There is also a base level of illness which can be quite severe even at rest.
  10. Repeated overexertion can harm the patient's chances for future improvement in M.E. Patients who are able to avoid overexertion have repeatedly been shown to have the most positive long-term prognosis.
  11. Not every M.E. sufferer has 'safe' activity limits within which they will not exacerbate their illness: this is not the case for very severely affected patients.


30% of M.E. patients are housebound and/or bedbound and are severely limited with even basic movement and communication. Cognitive disability can be very pronounced in M.E., just as much as can physical disability.

This information is based upon an enormous body of clinical information and research. Although M.E. can cause many different symptoms the major features of epidemic and sporadic M.E. are distinct and almost identical from one patient to the next. M.E. is a severely disabling, distinct, easily recognisable and testable disease entity.

More information

To read or download an extended and fully referenced version of the above text, please see the The comprehensive M.E. symptom list page.

Additional relevant links:

Extra information: Is 'fatigue' an essential M.E. symptom?

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.

M.E. is not synonymous with being tired all the time. If a person is 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 or Parkinson’s disease. Fatigue is a symptom of many different illnesses – but it is not a defining symptom of M.E., or an essential symptom of M.E. Some patients with M.E. may suffer with fatigue as a minor symptom, but many will not.

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, the science is very clear on this point. 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.

What defines M.E. is not ‘chronic fatigue’ but a specific type of damage to the brain. M.E. is an infectious neurological illness of extraordinarily incapacitating dimensions that affects virtually every bodily system – not a problem of unexplained ‘fatigue' or exhaustion.

For more information on this topic please see: The comprehensive M.E. symptom list and  What is Myalgic Encephalomyelitis? 

Many M.E. experts (and M.E. sufferers) have spoken out about against 'fatigue' being the defining features of M.E., see: M.E. is not defined by 'fatigue' and also the Quotes section for more information plus What it feels like to have Myalgic Encephalomyelitis: A personal M.E. symptom list and description of M.E.

The Fatigue Schmatigue paper explains how the fraudulent 'fatigue' construct came into being and how the M.E. community can and MUST play an active part in debunking this myth. This paper is aimed not at the public but at M.E. sufferers and other members of the M.E. community and is highly recommended.

Extra information: A warning on misdiagnosing M.E.

It should not be assumed that because one may have some of the symptoms on the list that one necessarily has 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 possible. M.E. cannot be accurately diagnosed merely on the presence of a certain percentage of possible M.E. symptoms. Those with Lyme disease may see many of their symptoms listed in M.S. or M.E. symptom lists, but this does not mean that Lyme disease is the same as M.S. or M.E. The same is true of many different diseases. Many diseases share a few symptoms, but what is important is the very different causes of these symptoms and the very different pathology and response to treatment seen in each of these patient groups.

None of these patient groups has the same cause of symptoms as seen in M.E. as none of these patient groups share the pathology of M.E. (For example, most of the symptoms of M.E. are caused by cardiac insufficiency and the associated reduced circulating blood volume of up to 50%. This can be so severe as to lead to death in M.E., in some cases. Yet this problem of cardiac insufficiency and reduced circulating blood volume simply does NOT OCCUR in these non-M.E. diseases.)

M.E. patients can be separated very easily and clearly from those with Lyme disease, various post-viral fatigue syndromes, candida, Bechet's disease, vitamin deficiencies, depression and other mental disease and so on when the onset of the disease is taken into consideration (unlike most of these diseases, the onset of M.E. is always sudden or acute) and when an evaluation of the core and unique symptoms of M.E. is done along with some of the tests used to confirm a M.E. diagnosis. M.E. should never be diagnosed based on a superficial analysis of non-core M.E. symptomatology. See: Testing for M.E. for more information on the diagnosis of M.E.