After being hospitalised with pneumonia, cardiac arrhythmia and soaring BP and heart rate, I am on Warfarin, beta blocker Bisoprolol and the diuretic Furosemide, with a Glyceryl Trinitrate (GTN) spray for angina episodes. (1) While a diuretic was understandable while I had pneumonia, if a problem with CFS is low blood volume wouldn’t a diuretic be counterproductive now, decreasing blood volume further when it is already too low? (2) While I suffer from angina, my angiogram was clear. My angina doesn’t seem to be caused by the usual culprit of narrowed blood vessels reducing oxygen supply to cardiac muscles. It does fit the CFS explanation of mitochondria in the heart not producing enough ATP fuel, and the heart having to switch to anaerobic respiration, with a resulting build up of lactic acid and muscle pain. In normal angina, GTN spray expands the blood vessels allowing more oxygen to the heart - problem solved. But if oxygen supply is ok, for someone with CFS and resulting low blood volume, wouldn’t GTN spray opening up the blood vessels mean the heart has to work even harder pumping blood to the brain?