ME (Myalgic Encephalomyelitis) is a severely debilitating neurological illness estimated to affect between 150,000 and 250,000 people in the U.K. It may be diagnosed as Chronic Fatigue Syndrome (CFS) or Post Viral Fatigue Syndrome (PVFS).
It is characterised by a range of neurological or cognitive symptoms including severe and long-lasting payback and slow recovery times associated with even minor activities (post-exertional fatigue) which can affect cognitive processes as much as physical ones. The World Health Organisation defines ME as a neurological illness. Patients are also prone to relapses which may take the form of the original systemic illness, or fresh episodes of muscular or other symptoms.
The 2007 NICE guidelines states that ME/CFS is a relatively common illness; and that its physical symptoms can be as disabling as multiple sclerosis, congestive heart failure and other chronic conditions; and that it places a substantial burden on patients, families and carers, and on society.
Symptoms can range from mild to severe to life-threatening and can include:
The cause of ME/CFS is still unknown, but there is unlikely to be a single causative agent. Several past epidemics appear to have been triggered by an outbreak of an infection which then subsided, and still today many patients report a variety of contributing factors (including infectious, traumatic, environmental) all of which can lead to a condition which shares a common set of symptoms.
It is estimated that between 150,000 and 250,000 people in the UK have ME/CFS, a prevalence higher than HIV infection or multiple sclerosis. It is twice as commonly reported in women as men. Studies indicate that most people with ME/CFS are unable to work to full capacity and that a significant number (from 10 to 25%) are effectively house or bed-bound. It is now known that ME/CFS affects all social groups and all ages, including children. The course of the illness can be extremely variable; some people improve quite quickly, while many others develop stable chronic illness or experience a severe and debilitating downward course over many years.