Simpson, L O, Shand, B I, Olds, R J · Pathology · 1986 · DOI
This study examined whether blood flows differently in people with ME/CFS compared to healthy people. Researchers tested blood samples and found that in the early stages of ME/CFS, blood may not flow as easily through tiny blood vessels, which could reduce oxygen delivery to tissues. However, in long-term ME/CFS, these blood flow problems were not observed.
Blood flow problems are a plausible mechanism for ME/CFS symptoms, particularly post-exertional malaise and microvascular dysfunction. This study provides early evidence that rheological changes may distinguish acute from chronic ME/CFS phases, potentially guiding future diagnostic or treatment approaches targeting circulation.
This pilot study does not prove that blood rheology abnormalities cause ME/CFS symptoms or that they are present in all patients. The cross-sectional design cannot establish whether rheological changes precede symptom onset, and the small sample size means findings may not generalize to the broader ME/CFS population. Additionally, correlation between filtration changes and clinical outcomes was not established.
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
Simpson, L O, Shand, B I, & Olds, R J (1986). Blood rheology and myalgic encephalomyelitis: a pilot study.. Pathology. https://doi.org/10.3109/00313028609059457
BibTeX
@article{mecfsatlas-simpson-1986-blood-rheology,
author = {Simpson, L O and Shand, B I and Olds, R J},
title = {Blood rheology and myalgic encephalomyelitis: a pilot study.},
journal = {Pathology},
year = {1986},
doi = {10.3109/00313028609059457},
note = {PubMed: 3093959},
url = {https://www.mecfsatlas.com/evidence/simpson-1986-blood-rheology},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-29. https://www.mecfsatlas.com/evidence/simpson-1986-blood-rheology
Contribute
Private, reviewed by a human. Not a public comment thread.