This is a medical question of type : causes 
 What causes Heart Valve Disease ? 
 Heart conditions and other disorders, age-related changes, rheumatic fever, or infections can cause acquired heart valve disease. These factors change the shape or flexibility of once-normal heart valves.
                
The cause of congenital heart valve disease isnt known. It occurs before birth as the heart is forming. Congenital heart valve disease can occur alone or with other types of congenital heartdefects.
                
Heart Conditions and Other Disorders
                
Certain conditions can stretch and distort the heart valves. These conditions include:
                
Advanced high blood pressure and heart failure, thiscan enlarge the heart or the main arteries.
                
Atherosclerosis in the aorta. Atherosclerosis is a condition in which a waxy substance called plaque builds up inside the arteries. The aorta is the main artery that carries oxygen-rich blood to the body.
                
Damage and scar tissue due to a heart attack or injury to the heart.
                
Rheumatic Fever
                
Untreated strep throat or other infections with strep bacteria that progress to rheumatic fever can cause heart valve disease.
                
When the body tries to fight the strep infection, one or more heart valves may be damaged or scarred in the process. The aortic and mitral valves most often are affected. Symptoms of heart valve damage often dont appear until many years after recovery from rheumatic fever.
                
Today, most people who have strep infections are treated with antibiotics before rheumatic fever occurs. If you have strep throat, take all of the antibiotics your doctor prescribes, even if you feel better before the medicine is gone.
                
Heart valve disease caused by rheumatic fever mainly affects older adults who had strep infections before antibiotics were available. It also affects people from developing countries, where rheumatic fever is more common.
                
Infections
                
Common germs that enter the bloodstream and get carried to the heart can sometimes infect the inner surface of the heart, including the heart valves. This rare but serious infection is called infective endocarditis.
                
The germs can enter the bloodstream through needles, syringes, or other medical devices and through breaks in the skin or gums. Often, the bodys defenses fight off the germs and no infection occurs. Sometimes these defenses fail, which leads to infective endocarditis.
                
Infective endocarditis can develop in people who already have abnormal blood flow through a heart valve as the result of congenital or acquired heart valve disease. The abnormal blood flow causes blood clots to form on the surface of the valve. The blood clots make it easier for germs to attach to and infect the valve.
                
Infective endocarditis can worsen existing heart valve disease.
                
Other Conditions and Factors Linked to Heart Valve Disease
                
Many other conditions and factors are linked to heart valve disease. However, the role they play in causing heart valve disease often isnt clear.
                
Autoimmune disorders. Autoimmune disorders, such as lupus, can affect the aortic and mitral valves.
                
Carcinoid syndrome. Tumors in the digestive tract that spread to the liver or lymph nodes can affect the tricuspid and pulmonary valves.
                
Diet medicines. The use of fenfluramine and phentermine (fen-phen) sometimes has been linked to heart valve problems. These problems typically stabilize or improve after the medicine is stopped.
                
Marfan syndrome. Congenital disorders, such as Marfan syndrome and other connective tissue disorders, can affect the heart valves.
                
Metabolic disorders. Relatively uncommon diseases (such as Fabry disease) and other metabolic disorders (such as high blood cholesterol) can affect the heart valves.
                
Radiation therapy. Radiation therapy to the chest area can cause heart valve disease. This therapy is used to treat cancer. Heart valve disease due to radiation therapy may not cause symptoms until years after the therapy.