An enlarged heart (cardiomegaly) isn't a disease, but rather a sign of another condition.
The term "cardiomegaly" refers to an enlarged heart seen on any imaging test, including a chest X-ray. Other tests are then needed to diagnose the condition causing your enlarged heart.
You may develop an enlarged heart temporarily because of a stress on your body, such as pregnancy, or because of a medical condition, such as the weakening of the heart muscle, coronary artery disease, heart valve problems or abnormal heart rhythms.
Certain conditions may cause the heart muscle to thicken or one of the chambers of the heart to dilate, making the heart larger. Depending on the condition, an enlarged heart may be temporary or permanent.
An enlarged heart may be treatable by correcting the cause. Treatment for an enlarged heart can include medications, medical procedures or surgery.