Our heart has four chambers – the left atrium, the right atrium, the left ventricle and the right ventricle. Between the left and right ventricles is a “wall” – a medical term for the septum, which is normally thin, but if it becomes hypertrophic, it can affect the flow of blood in and out of the heart, causing obstruction of blood flow, which is called hypertrophic obstructive cardiomyopathy. The diagnosis of hypertrophic obstructive cardiomyopathy can be detected mainly by echocardiography, and in addition, typical patients can hear murmurs. Common clinical manifestations include chest tightness and palpitations after activity. In patients with only hypertrophic cardiomyopathy but no obstruction, only regular observation and follow-up are required and no medication is needed. In patients with mild obstruction, the blood return can be relieved by medication. In patients with severe obstruction, surgery can reduce the probability of sudden death from exercise. For patients with a family history, first-degree relatives are advised to review cardiac ultrasound every three years to understand disease progression. Daily living should be done with attention to emotional control, and maintaining good habits is essential to prevent deterioration. For patients with symptoms, they should seek prompt medical attention and cooperate with their doctors to receive regular treatment.