Myalgic encephalomyelitis / chronic fatigue syndrome (ME/CFS) (related)

Myalgic encephalomyelitis, also called chronic fatigue syndrome, is autoimmune-related or suspected by some researchers, though its cause is not established. It is a complex, long-term illness affecting the nervous, immune, and energy-producing systems, often beginning after an infection. Immune dysregulation is one of several leading areas of research, and studies describe reduced natural killer cell activity, T-cell exhaustion, and diverse autoantibodies in many patients, together suggesting an autoimmune component without confirming one as the cause. Other research threads point to metabolic and neuroendocrine changes, and no single marker has been confirmed.

ME/CFS mostly affects adults, with peak onset between twenty and forty-five and a female-to-male ratio near three to one. Prevalence estimates vary by study, from roughly 0.3 to just under 1 percent of the population.

Common signs

Profound fatigue not relieved by rest, post-exertional malaise (a worsening of symptoms after even small physical or mental effort), unrefreshing sleep, difficulty with memory and concentration (brain fog), lightheadedness or worsening symptoms on standing, and pain.

This is a plain-language summary for orientation, not a diagnosis. Mechanisms are described as current understanding, not settled fact. Work with your own clinician for your care.