Category:British advocates or allies

myalgic encephalomyelitis (ME) - A disease often marked by neurological symptoms, but fatigue is sometimes a symptom as well. Some diagnostic criteria distinguish it from chronic fatigue syndrome, while other diagnostic criteria consider it to be a synonym for chronic fatigue syndrome. A defining characteristic of ME is post-exertional malaise (PEM), or post-exertional neuroimmune exhaustion (PENE), which is a notable exacerbation of symptoms brought on by small exertions. PEM can last for days or weeks. Symptoms can include cognitive impairments, muscle pain (myalgia), trouble remaining upright (orthostatic intolerance), sleep abnormalities, and gastro-intestinal impairments, among others. An estimated 25% of those suffering from ME are housebound or bedbound. The World Health Organization (WHO) classifies ME as a neurological disease.

chronic fatigue syndrome (CFS) - A fatigue-based illness. The term CFS was invented invented by the U.S. Centers for Disease Control as an replacement for myalgic encephalomyelitis (ME). Some view CFS as a neurological disease, others use the term for any unexplained long-term fatigue. Sometimes used as a the term as a synonym of myalgic encephalomyelitis, despite the different diagnostic criteria.