Patient has to stand still in test, and not fidget, which most sufferers do automatically, which pumps the blood through the muscles. Most patients felt nauseous, pale, headache, crying when the test was stopped. Usually ask the patient to say when they can't do it anymore. 8ml of mercury. Almost no blood to brain.
Most sufferers continue to stand even though they are in severe distress.
An orthostatic illness. We put out adrenaline to help circulate the blood - but this doesn't work when we stand up. One patient had hypertension, had a high BP response to low blood volume. Gave a diuretic to get rid of some fluid. Felt good for next 24-48 hours.