Chronic fatigue syndrome

Chronic fatigue syndrome, also called myalgic encephalomyelitis (ME/CFS), is a lasting illness involving multiple body systems that often limits everyday activity. Anyone can develop it, including children, but it is most common in middle age and adult women are affected more often than men. The cause is unknown; researchers are studying infections, immune changes, physical or emotional stress, changes in how cells obtain energy and genetics. The core features are persistent severe fatigue that rest does not relieve, symptoms that worsen after physical or mental effort, and sleep problems. Memory and concentration difficulty or dizziness on standing may also be present. No specific test exists, so clinicians diagnose it from the history and examination after blood and urine tests exclude other illnesses. There is no cure; management is long-term and combines energy management, support, and medicines for particular symptoms such as pain or poor sleep.

Seek urgent care for an injury with deformity, inability to bear weight, or numbness. See a doctor for pain that lasts more than a few weeks, that wakes you at night, or that comes with fever, weight loss or morning stiffness. Call the local emergency number for any symptom that is sudden and severe. This page is a reference for healthcare professionals and does not replace an assessment.