Post-exertional malaise

Post-exertional malaise (PEM) is a worsening of many ME/CFS symptoms as a result of physical or mental exertion. It is often referred to as "the marker" by patients, ME/CFS organizatons, clinicians and researchers that work in the ME/CFS field. PEM can last for days to weeks after the exertion.

2015 Institute of Medicine report


This landmark report published in 2015 by the United States Institute of Medicine report, which assessed all the evidence available, concluded:

"'There is sufficient evidence that PEM is a primary feature that helps distinguish ME/CFS from other conditions'"

Pages 84-86 of the report describe the evidence for post-exertional malaise in ME/CFS patients.

Notable studies

 * 1999, Demonstration of delayed recovery from fatiguing exercise in chronic fatigue syndrome
 * 2013, Post-exertion malaise in chronic fatigue syndrome: symptoms and gene expression, Meyer et al, 2013
 * 2015, Myalgic Encephalomyelitis: Symptoms and Biomarkers, Jason et al, 2015
 * 2015, Changes in Gut and Plasma Microbiome following Exercise Challenge in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), Shukla et al, 2015



Notable articles

 * Suggestion to replace PEM (Post Exertional Malaise) with PAR (Post Activity Relapse), ME Blogg, 2015

Talks & interviews

 * 2016, Inducing Post-Exertional Malaise in ME/CFS: A Look at the Research Evidence (Peter Rowe)
 * 2015, Post-Exertion Malaise: The Intersection of Biology and Behavior, Dane Cook, Solve ME/CFS
 * 2012, Top 10 Things You Should Know About Post-Exertional Relapse (Staci Stevens)

Learn more

 * Post-Exertional Malaise in Chronic Fatigue Syndrome, Jennie Spotila, Solve ME/CFS, 2010
 * Post-Exertional Malaise: Cause and Effect, Jennie Spotila, Solve ME/CFS, 2012
 * Definition of Post-Exertional Malaise, About Health, 2015
 * Post-Exertional Malaise Video, ME/CFS Ghost, 2016
 * 2016, The Exercise Intolerance in POTS, ME/CFS and Fibromyalgia Explained?