Portal:Energy metabolism/Selected article/2

Post-exertional malaise (PEM) is a worsening of many ME/CFS symptoms as a result of physical or mental exertion. Patients, ME/CFS organizatons, clinicians and researchers that work in the ME/CFS field often referred to it as "the marker," i.e., the main symptom that differentiates ME and CFS from other fatiguing illnesses. PEM can last for days to weeks after the exertion. (more...)