As there is no specific test yet for diagnosing ME/CFS, before ME/CFS is considered, other illnesses must be ruled out.

• Rule out any neoplasia, any autoimmune disease, localized infection, chronic infection (endocarditis, Lyme's disease, tuberculosis), fungal infection (histoplasmosis), parasite infection (toxoplasmosis, amoebiasis, giardiasis), viral infection (HbSAg,HIV).

• Rule out any chronic psychiatric illness, inflammatory disease (sarcoidosis, Wegener, hepatitis C), endocrine disease (hypothyroidism, Addison's, Cushing's, diabetes), alcohol or drug dependency, medication side effects.

CRITERIA FOR DIAGNOSING ME/CFS

The illness must persist for at least 6 months.

1. FATIGUE: The patient must have a significant degree of new onset, unexplained, persistent, or recurrent physical and mental fatigue that substantially reduces activity level and is usually made worse by exercise.

2. POST-EXERTIONAL MALAISE AND/OR FATIGUE: There is an inappropriate loss of physical and mental stamina, rapid muscular and cognitive fatigability, post-exertional malaise and/or fatigue and/or pain and a tendency for other associated symptoms within the patient's cluster of symptoms to worsen. There is a pathologically slow recovery period – usually 24 hours or longer.

3. SLEEP DYSFUNCTION: There is unrefreshed sleep or sleep quantity or rhythm disturbances such as reversed or chaotic diurnal sleep rhythms.

4. PAIN: There is a significant degree of myalgia. Pain can be experienced in the muscles and/or joints, and is often widespread and migratory in nature. The pain may also have neuralgic qualities. Often there are significant headaches of new type, pattern or severity.

5. NEUROLOGICAL / COGNITIVE MANIFESTATIONS:

Two or more of the following difficulties should be present:

confusion,
impairment of concentration and short-term memory consolidation,
disorientation,
difficulty with information processing, categorizing and word retrieval,
and perceptual and sensory disturbances – e.g. spatial instability and disorientation and inability to focus vision.
Ataxia, muscle weakness and fasciculations are common.

There may be overload phenomena: cognitive, sensory- e.g. photophobia and hypersensitivity to noise – and/or emotional overload, which may lead to "crash" periods and/or anxiety.

6. AT LEAST ONE SYMPTOM FROM TWO OF THE FOLLOWING CATEGORIES:

a) AUTONOMIC MANIFESTATIONS:

orthostatic intolerance –neurally mediated hypotension, postural orthostatic tachycardia syndrome, delayed postural hypotension; light-headedness; extreme pallor; nausea and irritable bowel syndrome; urinary frequency and bladder dysfunction; palpitations with or without cardiac arrhythmias; exertional dyspnea.

b) NEUROENDOCRINE MANIFESTATIONS:

loss of thermostatic stability – subnormal body temperature and marked diurnal fluctuation, sweating episodes, recurrent feelings of feverishness and cold extremities; intolerance of extremes of heat and cold; marked weight change – anorexia or abnormal appetite; loss of adaptability and worsening of symptoms with stress.

C) IMMUNE MANIFESTATIONS:

Tender lymphnodes, recurrent sore throat, recurrent flu-like symptoms, general malaise, new sensitivities to food, medications and/or chemicals.