Kujawski, Sławomir, Słomko, Joanna, Hodges, Lynette et al. · Journal of clinical medicine · 2021 · DOI
This study looked at 101 ME/CFS patients to understand post-exertional malaise (PEM)—the worsening of symptoms after activity that many patients experience. Researchers measured blood pressure, nervous system function, and fatigue levels in patients with and without PEM. They found that patients with PEM had higher mental fatigue, lower central blood pressure, and greater nervous system imbalance at rest, but the researchers caution that these findings need to be confirmed by larger studies.
Understanding what distinguishes patients with PEM from those without could help clinicians identify patients at highest risk and develop targeted interventions. This study begins to bridge pathophysiological mechanisms—autonomic dysfunction and hemodynamic changes—with the clinical hallmark symptom of ME/CFS, potentially opening new avenues for diagnosis and treatment.
This study does not establish causation—it cannot prove that mental fatigue or sympathetic activity cause PEM, only that they are associated. The lack of statistical significance after multiple testing correction means these associations are preliminary and may not be real. Additionally, the small sample size and cross-sectional design prevent generalization to all ME/CFS patients.
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →
The first block is for the primary paper and is the citation you should use in research work. The atlas-snapshot line only applies if you are specifically referring to this atlas’s reading of the paper on the date shown.
Primary citation
Kujawski, Sławomir, Słomko, Joanna, Hodges, Lynette, Pheby, Derek F H, Murovska, Modra, Newton, Julia L, et al. (2021). Post-Exertional Malaise May Be Related to Central Blood Pressure, Sympathetic Activity and Mental Fatigue in Chronic Fatigue Syndrome Patients.. Journal of clinical medicine. https://doi.org/10.3390/jcm10112327
BibTeX
@article{mecfsatlas-kujawski-2021-post-exertional,
author = {Kujawski, Sławomir and Słomko, Joanna and Hodges, Lynette and Pheby, Derek F H and Murovska, Modra and Newton, Julia L and Zalewski, Paweł},
title = {Post-Exertional Malaise May Be Related to Central Blood Pressure, Sympathetic Activity and Mental Fatigue in Chronic Fatigue Syndrome Patients.},
journal = {Journal of clinical medicine},
year = {2021},
doi = {10.3390/jcm10112327},
note = {PubMed: 34073494},
url = {https://www.mecfsatlas.com/evidence/kujawski-2021-post-exertional},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-28. https://www.mecfsatlas.com/evidence/kujawski-2021-post-exertional
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