[Recognizing and managing post-exertional malaise in primary care]

Post-exertional malaise (PEM) is a syndrome characterized by a worsening of symptoms after physical, cognitive, or emotional exertion. It presents as increased fatigue, usually accompanied by other clinical symptoms, such as muscle pain or cognitive impairment. First described in patients with chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME), PEM is now recognized as a hallmark of post-infectious syndromes that have received increasing attention through the emergence of long COVID. PEM is a distinguishing symptom of these conditions, and its early detection and appropriate management are essential to prevent long-term functional decline of affected patients. This review describes the definition and clinical impact of PEM and summarizes current recommendations for its management.