What is a heart valve disorder? As blood flows in and out of the heart, it passes through four valves: mitral, aortic, tricuspid and pulmonary. These tissue flaps push blood from the small chambers of the heart (atria) into the large chambers (ventricles), and also direct blood flow out of the ventricles into the rest of the body. When the valves are working correctly, they prevent blood from flowing backwards. However, valve damage or disease can disrupt blood flow in several ways. The most common types of valvular heart disease are: Regurgitation, which is blood flowing backwards, such as from a large chamber to a small chamber Stenosis, which makes the valve stiff and restricts blood flow through the valve Atresia, a condition usually present at birth in which a heart valve lacks an opening altogether Heart valve problems more commonly affect the mitral valve (in the form of mitral valve prolapse, which causes regurgitation) and the aortic valve (often in the form of stenosis, which restricts the amount of oxygenated blood flowing to the body’s tissues), but valve disorders also can cause pulmonic stenosis and tricuspid regurgitation. Heart valve disease can affect anyone of any age. Babies can be born with malformed valves, such as a bicuspid aortic valve. In this congenital heart defect, the aortic valve has only two tissue flaps instead of the usual three. Bicuspid aortic valve can lead to aortic regurgitation. In some cases, a congenital heart valve defect may not cause problems until later in life. Other heart conditions can also cause valve problems. Many people with heart valve disorders do not experience symptoms. Instead, a doctor diagnoses the condition when he or she hears an abnormal heart sound called a murmur. A heart murmur is not necessarily dangerous, even if it’s due to a heart valve defect. When people do develop symptoms related to valvular disorders, they often experience heart palpitations, fainting, or dizziness. If you experience any signs of a heart condition, you should seek medical care. Left untreated, valvular disorders can lead to complications like stroke.