fatigue syndrome chronic fatigue syndrome 780.71 http://purl.bioontology.org/ontology/MEDDRA/10008874 http://purl.bioontology.org/ontology/MESH/D015673 http://purl.bioontology.org/ontology/SNOMEDCT/52702003 http://purl.obolibrary.org/obo/DOID_8544 http://purl.obolibrary.org/obo/NCIT_C3037 http://www.ebi.ac.uk/efo/EFO_0004540 https://en.wikipedia.org/wiki/Category:Chronic_fatigue_syndrome https://en.wikipedia.org/wiki/Chronic_fatigue_syndrome https://homosaurus.org/terms/chronicFatigueSyndrome https://www.wikidata.org/wiki/Q209733 A clinical diagnosis characterized by an unexplained persistent or relapsing chronic fatigue that is of at least six months' duration, is not the result of ongoing exertion, is not substantially alleviated by rest, and results in substantial reduction of previous levels of occupational, educational, social, or personal activities. Common concurrent symptoms of at least six months duration include impairment of memory or concentration, diffuse pain, sore throat, tender lymph nodes, headaches of a new type, pattern, or severity, and nonrestorative sleep. CFS myalgic encephalomyelitis/chronic fatigue syndrome myalgic encephalomyelitis