Cardiovascular and autonomic dysfunction have been suggested to underly the symptoms accompanying CFS (chronic fatigue syndrome).

In the present issue of Clinical Science, Hurwitz and colleagues have investigated whether deficits were present in cardiac output and blood volume in a cohort of patients with CFS and whether these were linked to illness severity and sedentary lifestyle.

The results clearly demonstrated reduced cardiac stroke volume and cardiac output in more severely afflicted patients with CFS, which is primarily attributable to a measurable reduction in blood volume.

Similar findings are observed in microgravity and bedrest deconditioning, in forms of orthostatic intolerance, and to a lesser extent in sedentary people. The circulatory consequences of reduced cardiac output may help to account for many of the findings of the syndrome.