Abnormal breathing patterns and hyperventilation are common in patients with chronic fatigue syndrome during exercise.
Mancini, Donna M, Brunjes, Danielle L, Cook, Dane et al. · Frontiers in medicine · 2025 · DOI
Quick Summary
Researchers studied how patients with ME/CFS breathe during exercise and found that many breathe abnormally in ways that healthy people do not. Specifically, 42% of ME/CFS patients showed irregular breathing patterns, and 32% were breathing too fast and too deeply (hyperventilation). These breathing problems were much more common in ME/CFS patients than in the healthy control group, suggesting that abnormal breathing may be contributing to the fatigue and breathlessness patients experience.
Why It Matters
Abnormal breathing patterns are a potentially modifiable factor in ME/CFS that has received limited investigation independent of long COVID. If dysfunctional breathing and hyperventilation contribute to exertional symptoms, targeted respiratory interventions could represent a novel therapeutic approach for ME/CFS patients. This work highlights a physiological abnormality that deserves further investigation as a possible treatment target.
Observed Findings
42.1% of ME/CFS patients met criteria for dysfunctional breathing compared to 16% of controls (p<0.02)
32% of ME/CFS patients exhibited chronic hyperventilation versus 4% of controls (p<0.01)
9 ME/CFS patients had both hyperventilation and dysfunctional breathing, while no control participants exhibited both conditions
ME/CFS patients with hyperventilation had significantly higher ventilatory efficiency ratios (VE/VCO₂: 34.7±7.2 vs 28.1±3.8, p<0.001)
83% of hyperventilating ME/CFS patients had either elevated VE/VCO₂ ratios or dysfunctional breathing compared to 44% of non-hyperventilators (p<0.01)
Inferred Conclusions
Dysfunctional breathing and hyperventilation are common physiological abnormalities in ME/CFS occurring independently of COVID-19 infection
These breathing pattern abnormalities could represent a new therapeutic target for ME/CFS symptom management
The high concordance between hyperventilation and elevated ventilatory efficiency suggests these may represent related or overlapping pathophysiological phenomena in ME/CFS
Remaining Questions
Do abnormal breathing patterns contribute causally to ME/CFS symptoms or are they secondary adaptations to underlying pathophysiology?
What This Study Does Not Prove
This study does not prove that abnormal breathing patterns cause ME/CFS symptoms or exertional symptom exacerbation—it only documents that they occur more frequently in ME/CFS patients. The cross-sectional design cannot establish whether breathing dysfunction develops as a primary ME/CFS feature, as a secondary adaptation, or as a coping mechanism. It also does not demonstrate whether correcting these breathing patterns would improve patient outcomes.
Could respiratory rehabilitation or breathing retraining interventions reduce symptoms and improve exercise tolerance in patients with these breathing abnormalities?
What are the underlying mechanisms driving dysfunctional breathing and hyperventilation in ME/CFS (e.g., autonomic nervous system dysfunction, altered chemoreceptor sensitivity, deconditioning)?
Do breathing pattern abnormalities persist across repeated testing or vary with disease activity and symptom severity?