PEM is the worsening of symptoms following physical or mental exertion, and is the hallmark feature of ME/CFS.
✦ AI summary
Post-exertional malaise (PEM) — a worsening of symptoms after physical, cognitive, or emotional effort — is described across these sources as a defining feature of ME/CFS and also of Post-COVID Condition. Researchers are studying its biological underpinnings from many angles: one large study is examining neuroinflammation, gut microbiota, autonomic and nervous system function, and stress responses in ME/CFS patients, tracking PEM through questionnaires and lab tasks before and after rehabilitation therapy [1]. Other work looks for blood-based biomarkers, such as differences in extracellular vesicle proteins in plasma [2], while a separate review proposes a more speculative model linking low-dose radiation exposure, mitochondrial dysfunction, and immune changes to ME/CFS and PEM, describing it as still unproven and exploratory [7].
On the clinical/functional side, one study found that muscle strength (handgrip) testing was lower in people with suspected ME/CFS compared to healthy people, but it didn't correlate well with how long their PEM lasted and couldn't reliably distinguish ME/CFS from other fatigue conditions [9]. Another retrospective study found people with ME/CF
This is an AI-generated summary of the sources below — not medical advice. Always talk to a doctor or pharmacist about your own situation.
Symptom flare after exertionSevere fatigueCognitive worseningPain increaseSleep disruptionFlu-like symptoms
Multimodal approach to identify neuropsychophysiological subgroups in myalgic encephalomyelitis/chronic fatigue syndrome and their relevance for rehabilitation: protocol for a mechanistic cross-sectional and longitudinal study.
Myalgic Encephalomyelitis (ME)/Chronic Fatigue Syndrome (CFS) is a debilitating condition characterized by severe fatigue and post-exertional malaise (PEM). Reported neuropsychophysiological abnormalities suggest ME/CFS is multifactorial, but current knowledge remains fragmented. This study protocol…
Exploring differences in protein cargo of extracellular vesicles from ME/CFS patient plasma compared to healthy controls.
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a chronic and debilitating disease characterized by post-exertional malaise, fatigue and pain. Yet, its underlying biological mechanisms remain poorly understood. Extracellular vesicles (EVs) are nanoparticles carrying biological cargo a…
Photopolymerizable placenta-derived ECM hydrogel enhances hUC-MSC-mediated wound healing via coordinated immunomodulation and angiogenesis.
Mesenchymal stromal/stem cells (MSCs) hold great promise for regenerative medicine due to their potent immunomodulatory properties and favorable safety profile. However, their low survival, poor retention, and limited engraftment in injured tissues remain major barriers to clinical efficacy. Here, w…
ADDRESS-LC: study protocol for a phase 2, triple-blind, randomised, placebo-controlled trial to evaluate the efficacy and safety of bezisterim (NE3107) in adults with long COVID.
Long COVID is a debilitating condition consisting of prolonged neurological symptoms such as cognitive impairment ('brain fog') and sleep disturbance. Symptoms may be associated with ongoing neuroinflammation from the persistence of a viral reservoir, activation of other viruses, protracted macropha…
POCUS in pediatric arrest (Res-US pulse check): development and evaluation of a simulation-based curriculum.
Pediatric Advanced Life Support guidelines recommend pulse assessment within 10-s, yet manual palpation during pediatric cardiac arrest is often inaccurate. Point-of-care ultrasound (POCUS) can improve detection of arterial pulsatility, identify cardiac activity or standstill, and diagnose reversibl…
Unveiling Key Factors in Determining Biodegradable Mulching Film Adoption Through Evolutionary Game Analysis.
Polyethylene mulching films (PEM) are widely used in agriculture to improve water-use efficiency, regulate soil temperature, and enhance crop yields, but their poor degradability leads to persistent soil residues and high recovery costs. Biodegradable mulching films (BDM) offer a promising alternati…
Wearable Heart Rate Variability Monitoring, Autonomic Dysfunction and Post-exertional Malaise in Long COVID: An Observational Study.
Patients with long coronavirus disease (COVID) experience disabling fatigue, autonomic dysfunction, reduced exercise capacity and post-exertional malaise (PEM). Heart rate variability (HRV) can evaluate autonomic function and monitor overexertion, potentially helping to mitigate PEM. This study aime…
Differences in diagnostic coding in long COVID: sociodemographic and symptom interference factors.
We aimed to test associations of participant-reported Long COVID symptom interference with life activities with Long COVID symptoms, presence of U09.9 Long COVID diagnosis code, demographics, and clinical factors. In a subgroup, we documented coding related to Long COVID and post-exertional malaise…