The prognosis of hypertrophic cardiomyopathy varies greatly, and it is the primary cause of sudden death in adolescents and athletes because it can progress to end-stage heart failure. Additionally, a small percentage may experience heart failure, atrial fibrillation, and embolism, but many patients have mild symptoms and can have a life expectancy close to normal. For the treatment of hypertrophic cardiomyopathy, adequate sudden death risk assessment and ICD prevention should be conducted. Because hypertrophic cardiomyopathy is the most common cause of sudden cardiac death in young people and athletes, an ICD can effectively prevent the occurrence of sudden death. Preventing high-risk factors, including previous cardiac arrest, one or more sudden deaths in first-degree relatives, severe left ventricular hypertrophy, and findings of repetitive non-sustained ventricular tachycardia on a 24-hour Holter monitor, low blood pressure during exercise, and unexplained syncope, especially during exercise, poses a high risk of sudden death in these patients.