[Primary and secondary hypertension in polyclinical patients]

Hypertension was found in 854 (10.4%) of 8228 patients (3657 females, 4571 males) seen in our outpatient clinic during 1975. Essential (primary) hypertension was found in 92.9% (n = 793) of all hypertensives. Among secondary forms of hypertension (7.1%) renal hypertension, with a rate of 5.8%, was the commonest form (hypertension of renal-parenchymatous origin 4.9%, renovascular hypertension 0.8%, hypertension associated with unilateral hydronephrosis 0.1%. In 2 patients (0.2%) the underlying disease was primary aldosteronism and in 5 (0.6%) coarctation of the aorta. In 4 female patients (0.5%) the hypertension was caused by oral contraceptives. Patients with essential hypertension had higher body weight than those with normal blood pressure. These differences were statistically significant in young and middle-aged patients. Our results show a very high percentage of essential hypertension. In only 18 (2.1%) of 854 hypertensives was a curable form of high blood pressure found (hypertension caused by renal artery stenosis, hydronephrosis, aldosterone producing adenoma of the adrenal gland and oral contraceptives). The very low percentage of curable forms of hypertension should be kept in mind when deciding on expensive procedures in a search for secondary forms of high blood pressure.