What is Renovascular Hypertension (Renal Artery Stenosis)?
A. This is by far the commonest cause of secondary hypertension, and accounts for about 3 per cent of all cases of hypertension. It’s caused by a narrowing in one or both renal (kidney) arteries. This reduces the blood pressure and flow in the kidney, which responds by secreting a hormone called renin, which enters the blood stream and leads to the formation of a second hormone (angiotensin), which causes the blood pressure to go up. This helps to restore the flow to the blocked kidney. There are two quite distinct causes of renovascular hypertension. The first, which occurs in young people (particularly children and young women), is called fibromuscular dysplasia. There are one or more fibrous constrictions of the artery. An important aspect of this condition is that it hardly ever affects any arteries other than the ones supplying the kidneys. Nobody knows what causes it, although smoking may be a contributory factor; it usually does not run in families.
