[Hypertension from the nephrologist's point of view]

Secondary hypertension represents about 5-10% of all forms of hypertension, renal and renovascular being the commonest forms. Renal artery stenosis is the principal cause of renovascular hypertension due to atheromatous disease or fibromuscular dysplasia. Rapid sequence intravenous pyelogram, isotope renogram, captopril test and digital subtraction angiography or conventional arteriography, are the diagnostic procedures in the diagnosis of renal artery atenosis. Hypertension is also very common in parenchymal renal disease, mainly in chronic renal insufficiency. In this condition, the mechanism is more related to volume dependent factors than in renovascular hypertension which is mainly renin dependent. In the treatment of renal or renovascular hypertension the same type of drugs have been generally used as in essential hypertension although with some specific indications like the use of angiotensin-converting enzyme inhibitors in unilateral renal artery stenosis or furosemide in case of renal insufficiency. Revascularization by angioplasty or surgical bypass, may be indicated in renovascular hypertension.