What are the causes of aortic stenosis?

Age related calcification of the valve
This is the common cause. Deposits of calcium build up in the valve in some older people. It is not clear why this happens. This 'calcification' makes the valve stiff and open less easily. It can be mild and cause little narrowing. However, in time it can become more severe.

Rheumatic fever
Rheumatic fever is a condition that sometimes occurs during an infection with a bacterium (germ) called the streptococcus. You body makes antibodies to the bacterium to clear the infection. However, in some people the antibodies also 'attack' various parts of the body, in particular the heart valves. Inflammation of a valve may develop which can cause permanent damage and lead to thickening and scarring years later.

Other causes
Other causes of aortic stenosis are uncommon and include:

• Some congenital heart problems. It is then usually part of a complex heart deformity.
• Infection of the valve (endocarditis).
• An abnormality of the tissues just above or just below the valve. This may cause a narrowing and restrict blood flow, and cause problems identical to stenosis of the valve.