Mitral stenosis is a heart valve disorder that affects about 2 out of 10,000 people. Symptoms usually develop between the ages of 20 and 50. Congenital mitral stenosis alone is rare as it more often occurs as a component of complex abnormalities of the heart.

The actualy physiological effect of mitral stenosis is a contriction of the mitral valve. Blood cannot therefore pass from the left atrium to the left ventricle. This leads to all the problems associated with a bad heart, such as feeling easily exerted, and breathing difficulties. It can usually be easily diagnosed by the characteristic abnormality of the heart beat sound.

While drugs can control the symptoms in mild cases the only efective cure in heart valve surgery. The valve may have to be replaced with an artificial one.