People living with familial hypercholesterolemia are at risk of developing blockages in the arteries called atherosclerosis. These blockages can potentially lead to a heart attack or other cardiovascular diseases which can result in a reduced life expectancy. Without medical treatment, people with the most severe forms of familial hypercholesterolemia may not live beyond their 20s. However, with appropriate treatment, people can live with familial hypercholesterolemia into their 70s.