The prevalence of secondary and curable hypertension.

The prevalence of secondary and curable hypertension was studied retrospectively in 1000 patients. The concept of "secondary hypertension" was used when hypertension was combined with a disease which may have affected the individual's blood pressure. When this definition was applied, 47 of the patients displayed some form of secondary hypertension: stenosis of the renal artery in 10, renoparenchymal disease in 21, hydronephrosis in 3, and endocrine hypertension in 13 (8 of the latter were using oral contraceptives). The blood pressure normalized in 11 and improved in 7 of these patients after operative treatment of the underlying disease or, when appropriate, discontinuance of intake of contraceptive pills. The incidence of secondary hypertension in this and other series is low, and the number of patients with curable hypertension is even lower. In the majority of cases, secondary hypertension can be diagnosed by anamnesis, physical examination and simple tests of blood and urine. If this basic investigation can be extended, the incidence of stenosis of the renal artery should be examined in the first place. Hypertension in young patient and in patients who are difficult to treat often justifies a more extensive investigation.