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, mental, or emotional effort — is described in these sources as a core, defining feature of both ME/CFS and Long COVID [2][9][11]. Researchers are actively trying to figure out what's happening in the body during PEM: some studies point to brain activity changes, like altered electrical patterns in areas that control movement and sensation, linked to fatigue and "brain fog" [1]. Others are looking at blood and metabolic changes after exertion, such as shifts in lactate levels [5], differences in tiny cell particles called extracellular vesicles [3], a specific blood protein (haptoglobin) type linked to worse post-exertional brain function and oxygen use [7], and a proposed (but still unproven) theory involving blood vessel lining dysfunction [12]. One broader idea suggests PEM may come from multiple body systems (like metabolism and heart/blood vessel function) failing to coordinate properly after exertion, rather than one single cause [11]. On the treatment side, a large trial testing an antiviral drug for Long COVID (including exercise-related symptoms) found no meaningful benefit [10], while other ongoing studies are testing appro
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
Identifying EEG biomarkers of fatigue and brain fog in long COVID: insights from rest and movement-related brain activity.
Fatigue and brain fog are among the most reported symptoms in Long COVID (LC), yet their underlying neural mechanisms remain unclear. In this context, we aimed to identify neural correlates associated with LC symptoms. Electroencephalography (EEG) was used to quantify brain oscillatory activity duri…
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…
Gaps in physiotherapy capacity to provide Long COVID rehabilitation care.
Long COVID is a complex multisystemic condition often associated with persistent cardiorespiratory symptoms. Rehabilitation is key for managing symptoms, but there are questions about the capacity of rehabilitation professionals to provide effective care. This study assessed the capacity of physioth…
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…
Exercise lactate in post-COVID-19 condition: Pathophysiological signal, phenotyping tool, or candidate biomarker? A narrative review with a hypothesis-generating clinical observation.
Post-COVID-19 condition (PCC), commonly termed long COVID, is a heterogeneous multisystem disorder in which fatigue, exertional dyspnoea, post-exertional symptom exacerbation, and reduced exercise tolerance are prominent. No single laboratory measurement currently confirms or excludes PCC. Because l…
Total blood volume and red blood cell volume are not associated with orthostatic intolerance in adults with myalgic encephalomyelitis/chronic fatigue syndrome.
Orthostatic intolerance is common in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and may worsen daily functioning. Although hypovolemia has been proposed as a contributor, its relationship to objective orthostatic abnormalities remains uncertain. We examined whether measured blood-vo…
Guidance on Home-Based Care for People with Severe ME/CFS: A Transdisciplinary Expert Statement.
Many patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) have significant care needs. However, post-exertional malaise-the defining feature of ME/CFS-means that even minor physical, orthostatic, cognitive, or sensory stressors can trigger a disproportionate worsening of symptom…
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…