[Renovascular hypertension--a persistently difficult diagnostic problem]

Renal ischaemia, both unilateral or bilateral, is the cause of renin dependent hypertension but only at the beginning of kidney hypoperfusion. Long lasting renovascular hypertension is progressively becoming more and more independent from the renal renin-angiotensin (RA) system and finally mostly dependent from extrarenal hypertensinogenic factors. This is the reason, why assessment of the individual components of the renal RA system and anatomical or physiological methods of kidney imaging are becoming progressively less sensitive and less specific in the diagnosis of renovascular hypertension of long-term duration.