The indices of central hemodynamics were studied during hemiton therapy in 33 patients with stage IIA and IIB hypertensive disease by means of a noninvasive method--tetrapolar chest rheography. In patients with hypodynamic type of circulation the arterial pressure decreased already beginning with the first week of treatment due to a decrease in the arterial tonus and general peripheral resistance; the cardiac output practically did not change. During treatment cerebral and peripheral circulation improved significantly (according to the rheographic data) and the arterial tonus decreased. In 3-4 weeks of treatment, favourable shifts occurred in the reactions of general and regional hemodynamics in the orthostatic test. The overall changes were evidence that the compensatory-adaptational reactions of the arteries and veins had improved and the venous return had increased. In most patients treatment with hemiton led to lesser orthostatic decrease in arterial pressure and its greater lability during the day.