Move over POTS – Hypocapnia May be a Bigger Deal in ME/CFS

Postural orthostatic tachycardia syndrome (POTS) has always been thought to be the big deal regarding orthostatic intolerance (increased symptoms while standing or sitting) in chronic fatigue syndrome (ME/CFS).

That may be changing with a recent study, “Physiological assessment of orthostatic intolerance in chronic fatigue syndrome“, from Dr. Benjamin Natelson MD at the Icahn School of Medicine at Mount Sinai, and Elizabeth Unger of the Centers for Disease Control and Prevention (CDC). One had the feeling that Natelson – one of the first to uncover hypocapnia in ME/CFS – has been thinking the condition (low carbon dioxide levels in the breath) has not been given its proper due. If so, he’s probably right.

t’s not that it hasn’t been popping up – it has been. Systrom has found it in his invasive exercise studies, the Visser team found it during tilt table testing, and Naschitz also found it in his exciting run of ME/CFS/FM Israeli studies fifteen years ago. (Naschitz described it as “common” in fibromyalgia.). I imagine that name recognition is pretty low, though.

Hypocapnia has never been found in everyone with ME/CFS/FM, but it appears to be present in a substantial subset. Natelson and Mancini also found it during exercise testing, and Novak found it during tilt-table testing in people with long COVID.