I was curious if anyone on PR knows the statistics (if they even exist?) re: PWC's and pulmonary function testing? Is it common for PWC's to fail pulmonary testing (i.e. inhaling and exhaling into a spirometry machine, trying again with inhaler or med, lung diffusion testing, etc.) I am unclear if a person with ME/CFS would normally be able to complete and pass these tests vs. be too weak to complete them vs. fail them. Are there any studies on this topic? Am wondering if there is great variation in results vs. a trend that most pass or fail them? I am particularly interested in restrictive airway disease. Any info would be greatly appreciated! Thank you in advance to anyone who answers this.