MECFS

MECFS, short for myalgic encephalomyelitis/chronic fatigue syndrome, is a chronic, multi-system illness of unclear origin. It is characterized by severe, persistent fatigue that is not substantially relieved by rest and by a range of accompanying symptoms affecting the brain, immune, and autonomic systems. The condition is diagnosed on clinical grounds, and several diagnostic criteria have been developed, including the Fukuda criteria and Canadian Consensus criteria.

Core symptoms typically include post-exertional malaise, a worsening of symptoms after physical, mental, or emotional activity that can last 24 hours or longer; unrefreshing sleep; substantial reductions in activity levels; cognitive impairments often described as “brain fog”; orthostatic intolerance; and widespread or localized pain. Symptom severity can fluctuate, with periods of relative stability and episodes of relapse.

The cause of MECFS is not known, and there is no single diagnostic test or biomarker. Research points to possible immune, neuroinflammatory, metabolic, and autonomic nervous system involvement, and many cases begin after an acute infection or another stressor. Because symptoms overlap with other conditions, diagnosis requires careful medical evaluation and exclusion of other explanations.

Management is supportive and individualized, focusing on reducing symptom burden and improving function. Common strategies include energy-conservation techniques and pacing of activities, sleep optimization, pain management, and treatment of orthostatic intolerance. Some guidelines historically recommended graded exercise therapy or cognitive behavioral therapy, but these approaches remain controversial and are used selectively depending on the patient. Pharmacologic treatments may target specific symptoms such as pain, sleep disturbance, or mood issues, and multidisciplinary rehabilitation and social support are often important.

Epidemiology and prognosis vary; MECFS typically affects adults and is more common in women. The condition can be long-lasting and disabling, but some individuals experience improvements over time. Ongoing research seeks biomarkers, subtypes, and more effective therapies.