Heart muscle diseases, also known as cardiomyopathies, affect the heart's ability to pump blood effectively. These conditions can lead to heart failure, arrhythmias, and other serious complications. Common types include dilated cardiomyopathy, where the heart becomes enlarged, and hypertrophic cardiomyopathy, characterized by thickened heart walls. Causes of heart muscle diseases can vary and may include genetic factors, high blood pressure, and previous heart attacks. Symptoms often include shortness of breath, fatigue, and swelling in the legs or abdomen. Early diagnosis and treatment are essential for managing these conditions and improving quality of life.