The mitral valve is 1 of 4 valves in your heart. The mitral valve has 2 leaflets that open and close like a door with each heartbeat and permit blood to flow in only 1 direction.
Stenosis means narrowing.
Stenosis of the mitral valve keeps it from opening normally. Over time, the stenosis can cause the left atrium to enlarge and limit your ability to exercise. Two-thirds of all people with mitral stenosis in the U.S. are women. No one knows why. In adults, mitral valve stenosis is almost always the result of having had rheumatic fever.