Blood for catecholamine, bradykinins, plasma renin activity, aldosterone and plasma angiotensin II is drawn while the patient is supine and upright. Blood pressure is measured with a sphygmomanometer or an automated device (Dinamap). Normally, on assuming the upright posture, plasma norepinephrine and renin activity should double. Patients with autonomic failure typically show low supine levels of both norepinephrine and renin activity which failed to increase on assuming the upright posture. In contrast, patients with hyperadrenergic orthostatic hypotension typically have normal or exaggerated responses.