Hypertrophic cardiomyopathy (HCM or HOCM if obstructive) is a disorder in which the heart thickens for no apparent reason. The interventricular septum and the ventricles are the most usually afflicted sections of the heart. This causes the heart to be less effective at pumping blood and may also create electrical conduction difficulties. HCM patients may experience a variety of symptoms. People may have a variety of symptoms, including weariness, limb edoema, and shortness of breath. It can also cause chest pain or make you pass out. When a person is dehydrated, the symptoms may be exacerbated. Heart failure, an irregular heartbeat, and sudden cardiac death are all possible complications.

HCM is most usually inherited in an autosomal dominant manner from a person's parents. It is frequently caused by mutations in genes involved in the production of cardiac muscle proteins. Fabry disease, Friedreich's ataxia, and certain drugs like tacrolimus can all be genetic causes of left ventricular hypertrophy. Athlete's heart and hypertension are two more possible reasons of an enlarged heart (high blood pressure). A family history or pedigree, an ECG, an echocardiography, and stress testing are typically used to diagnose HCM. It is also possible to conduct genetic testing. The autosomal dominant type of HCM distinguishes it from other inherited causes of cardiomyopathy, whereas Fabry disease is X-linked and Friedreich's Ataxia is autosomal recessive.

Symptoms and other risk factors may influence treatment. Beta blockers and disopyramide are two medications that may be used. In patients with specific forms of irregular heartbeats, an implantable cardiac defibrillator may be advised. Those who do not improve with alternative treatments may need surgery, such as a septal myectomy or a heart transplant. The chance of dying from the condition is less than 1% each year with treatment.