What causes hypertrophic cardiomyopathy (HCM)?

Hypertrophic cardiomyopathy (HCM) is a complex type of heart condition characterized by the thickening and stiffening of the muscle of the left ventricle. This thickening can block blood flow to the rest of the body and causes the heart muscle to enlarge (hypertrophy). 

There are several probable causes of hypertrophic cardiomyopathy. The most common cause is genetics, wherein gene mutations cause the heart muscle to thicken. There are several different genes that can cause HCM. An individual can inherit a mutated gene from their parents and pass it on to their children. However, not all individuals with the genetic mutation will develop the symptoms or have the same severity of the condition. Some may carry the mutated gene without ever developing hypertrophic cardiomyopathy while others may develop various symptoms and complications. 

Other causes of hypertrophic cardiomyopathy include aging and high blood pressure. In some cases, HCM may develop due to unknown reasons.