Post-exertional malaise

Post-Exertional Malaise (PEM) is one of the main symptoms of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). PEM can be described as "a delayed and significant exacerbation of ME/CFS symptoms that always follows physical activity and often follows cognitive activity". PEM is considered a cardinal symptom by a number of the different diagnostic criteria for ME/CFS, including the International Consensus Criteria.

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