[Pathophysiology and laboratory examinations of essential hypertension--a review of recent topics].

Since the pathogenesis of essential hypertension has not yet been clarified, laboratory examinations are needed to identify secondary hypertension and to classify the patients with essential hypertension into subclasses. We reviewed the recent topics on hypertension-research related to laboratory examinations such as 1) recording of arterial pressure, 2) plasma renin activity and digitalis-like substances as the cause of essential hypertension, and 3) atrial natriuretic polypeptides and endothelin, as possible indices of atherosclerosis, one of major complications of hypertension.