- Myalgic Encephalomyelitis (M.E.)
- Chronic Fatigue Syndrome (CFS)
- Systemic Exertion Intolerance Disease (SEID)
- Chronic Fatigue Immune Deficiency Syndrome (CFIDS)
- Myalgic Encephalopathy
- Chronic Epstein-Barr virus (CEBV)
- Neuro-Inflammatory and Oxidative Fatigue
- Chronic Fatigue
- Infectious Venulitis
- Yuppie Flu
- Ramsay's Disease
- Akureyri Disease (Icelandic Disease)
- Tapanui Flu
- Postviral fatigue syndrome (PVFS)
- Royal Free Disease
- Epidemic neuromyasthenia
- Low Natural Killer Cell Disease
- Epidemic Vegetative Neuritis
- Neuroendocrineimmune Dysfunction Syndrome, or NDS
- Atypical poliomyelitis
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.
systemic exertion intolerance disease (SEID) - A term for ME/CFS that aims to avoid the stigma associated with the term "chronic fatigue syndrome", while emphasizing the defining characteristic of post-exertional malaise (PEM). SEID was defined as part of the diagnostic criteria put together by the Institute of Medicine (IOM) report of 10 February 2015.
Chronic Fatigue and Immune Dysfunction Syndrome (CFIDS) - Chronic Fatigue and Immune Dysfunction Syndrome is another term for Chronic Fatigue Syndrome, but one which emphasizes the immunological aspects of the disease. Popular in the 1990s, this term has apparently fallen into disuse.