Chronic fatigue syndrome

For a lay person:

Chronic fatigue syndrome, also called myalgic encephalomyelitis (ME/CFS), is long-lasting, disabling exhaustion that rest does not relieve and that gets worse after physical or mental effort. It often starts after a viral infection.

For a trained medical person:

Defined by substantially reduced function for at least six months, post-exertional malaise, unrefreshing sleep, and cognitive impairment or orthostatic intolerance. Other causes of fatigue (thyroid disease, anaemia, depression, sleep disorders) must be excluded. Management is symptomatic, with activity pacing; graded exercise is no longer recommended.

In Chinese medicine:

Maciocia's theory treats post-viral fatigue as a residual pathogenic factor — Dampness or Latent Heat lingering after an infection — on a background of deficiency, chiefly of the Spleen and Kidney. He presented this as a new theory, not a classical one.