Cardiomyopathy refers to a group of diseases that affect the heart muscle, making it harder for the heart to pump blood to the rest of the body. It can lead to heart failure, arrhythmias, and other serious health problems. Cardiomyopathy can be classified into several types, including dilated, hypertrophic, restrictive, and arrhythmogenic right ventricular cardiomyopathy, each with its own characteristics and causes.