Cardiomyopathy is a term used to describe a disease in which there is a weakened or abnormal heart muscle. The three most common subtypes include dilated, hypertrophic, and restrictive cardiomyopathy. Dilated cardiomyopathy, a common cause of heart failure, is an enlargement and thinning of the heart muscle and walls. Hypertrophic cardiomyopathy is characterized by thickening of the heart muscle walls and is a leading cause of death in young athletes. Restrictive cardiomyopathy occurs when heart muscles become stiff that can lead to improper blood filling and is often due to disease processes like amyloidosis and cancer. Treatment is important to prevent disease progression and begins with a complete workup (including genetic screening) before considering medications, surgical intervention, and/or implantable devices.