Congenital heart disease is a kind of malformation or heart defect that exists somewhere in the heart. In some cases it is a defect that can be found in one of the blood vessels of the heart. It is defined as congenital because the defect is present when a baby is born. It is strongly believed that these types of heart defects take place while the fetus is developing but it is not clear at what stage throughout the nine months that it takes hold. Out of every 1,000 children born, 8 to 10 have this condition.

Some babies show symptoms of congenital heart defects from the very beginning of their lives while other people will not show symptoms until later in their childhoods. In other cases, such a defect is not discovered until a person has become an adult. It is estimated that 500,000 American adults suffer from congenital heart disease.

Trying to discover the cause of congenital heart disease is not easy. Most of the time the cause of it is not known. Doctors and medical researchers have discovered factors that do seem to suggest an increased risk of developing this disease however. One of these risk factors is a chromosomal abnormality or a genetic abnormality such as Down syndrome. Women who drink alcohol, use drugs or take specific types of medication during the period of their pregnancy are more likely to give birth to children with congenital heart defects. When a woman contracts a maternal viral infection such as German measles (also known as rubella) during the first trimester of her pregnancy she is more likely to give birth to a child with this disease.

If someone in the family such as a parent, grandparent or brother or sister was born with a congenital heart defect then the risk of a child in the family being born with it is even higher. For example, the risk for the general population is eight in 1000 but it becomes 16 in 1000 for those who have a family member with it.

There is more than one type of congenital heart disease. Heart valve defects are very common and these are stenosis or narrowing of the heart valves or in severe cases, valves that are narrowed to the point that they do not allow blood through at all. Leaky valves also fall under the category of heart valve defects. Atrial and ventricular septal defects which are defects in the walls between the atria and ventricles of the heart cause some blood which is oxygenated and some blood which is not, to mix which can cause problems in both the right and left areas of the heart. Another type of congenital heart disease is abnormalities in the heart muscle, which can then cause heart failure.

Congenital heart disease can cause symptoms but often times there are no symptoms at all. Sometimes it is necessary to undergo medical tests to determine whether or not a person is afflicted with this disease. If symptoms do show themselves the two most common are shortness of breath and a decreased ability for exercise.