Renovascular hypertension is one of the most common forms of secondary hypertension and is due to a decreased blood flow to the kidneys. Usually, this blood flow is restricted because the artery to the kidneys has narrowed (renal artery stenosis).

Renal blood vessels narrow because of one of two conditions – atherosclerosis or fibromuscular dysplasia. Atherosclerosis is a disease in which arteries are hardened and narrowed as a result of plaque that has built up along the inside of the artery walls. Fibromuscular dysplasia is a condition in which cells from the artery wall overgrow, causing the artery to narrow.

Diagnosis of renovascular hypertension can be difficult because symptoms tend to be subtle or absent. However, it is very important to diagnose this condition because some medications used to treat high blood pressure may be detrimental or lethal if given to patients with severe renal artery stenosis. Renal artery stenosis may be treated with angioplasty or stenting.

Labile, or transient, hypertension is a temporary rise in blood pressure during stressful situations. Blood pressure then returns to normal. Many young people who have labile hypertension for several years go on to develop primary hypertension, especially if there is a family history of hypertension. However, even labile hypertension may result in complications such as heart disease, kidney disease and stroke if left untreated. It is often treated successfully with beta blockers or other medications and stress management.