As a cardiologist, I often get asked during clinic visits, “Doctor, today I had a physical examination and the doctor said I have an enlarged heart, what should I do?” What should I do?”. In fact, the term “cardiomegaly” is not a professional term, but generally speaking, “cardiomegaly” indicates organic lesions of the heart, including two lesions, one is “hypertrophy” and the other is “large”. The normal heart is like a “four-room” with four chambers, namely the left atrium, right atrium, left ventricle and right ventricle, which are separated by the heart muscle. The word “hypertrophy” refers to hypertrophy of the heart muscle, and the word “large” refers to enlargement of the heart. If we use the analogy of a room, “hypertrophy” means that the walls of the room are thickened, and “enlarged heart” means that the space of the room is enlarged. First of all, myocardial hypertrophy is mainly seen in the left ventricle. In addition to athletes, myocardial hypertrophy is considered physiological, in general, myocardial hypertrophy is all pathological. The most common cause of left ventricular hypertrophy is hypertension. Other causes include hypertrophic cardiomyopathy, aortic stenosis, and cardiac amyloidosis. Hypertension causes left ventricular hypertrophy mainly due to increased arterial blood pressure, the heart must compensate for the increased contraction to overcome the increased arterial pressure ejection resulting in left ventricular hypertrophy. Just as exercise makes our muscles bigger, the result of long-term “exercise” of the heart is myocardial hypertrophy, but myocardial hypertrophy is not good. Myocardial hypertrophy can lead to myocardial ischemia, which can affect the function of the heart in the long term. Many clinical studies have shown that myocardial hypertrophy is associated with coronary heart disease, heart failure, and sudden cardiac death. Myocardial hypertrophy can be diagnosed by performing electrocardiogram and echocardiogram. The main preventive and therapeutic measure is to control blood pressure. However, it is important to note that comprehensive blood pressure control is needed. Many patients attach great importance to the blood pressure measured by the doctor in the hospital, thinking that this blood pressure is the most accurate. In fact, this is a misconception. Because of the obvious fluctuations in blood pressure, the hospital blood pressure only reflects a very brief cross-section of the blood pressure level of a patient with hypertension. It is more important that the patient’s home self-measured blood pressure and, if necessary, 24-hour ambulatory blood pressure monitoring, reflect a more comprehensive picture of the patient’s blood pressure level. If home self-measurement and 24-hour ambulatory blood pressure can be well controlled, it can effectively prevent and treat hypertension-induced cardiac hypertrophy. The term “large” refers to an enlarged heart, usually the left ventricle is more common, and heart enlargement is the end result of all heart disease. The most common causes of heart enlargement include ischemic heart disease, hypertension, alcoholic cardiomyopathy due to heavy alcohol consumption, dilated cardiomyopathy, and heart valve disease. The presence of an enlarged heart can be checked by chest X-ray and echocardiography. Echocardiography can measure the size of each chamber of the heart, the thickness of the heart muscle, and can also tell us whether there are any lesions in the heart valves and the function of the heart, etc. It is the most common method to diagnose heart enlargement. If an enlarged heart is found, it is necessary to go to the hospital for a detailed examination to clarify the cause of the enlarged heart and to treat the cause. Generally speaking, heart enlargement is usually accompanied by heart failure, so the treatment for heart enlargement is mainly for heart failure. However, there are cases where the heart is enlarged and the heart is functioning well. Patients with enlarged hearts are at higher risk of heart failure and sudden cardiac death than the normal population and should be treated. The first treatment is based on the cause, such as treating myocardial ischemia if it is caused by cardiac ischemia, controlling blood pressure if it is related to high blood pressure, and stopping drinking alcohol if it is caused by alcohol consumption. All patients with heart enlargement accompanied by heart failure should be treated with standard medications. These include beta-blockers, such as betaxolol, bisoprolol, and carvedilol; angiotensin-converting enzyme inhibitors, such as various “prilosecs”, including ramipril and perindopril; and angiotensin receptor antagonists, such as various “sartans”, including angiotensin receptor antagonists, such as various “sartans”, including colesartan, valsartan, temisartan, etc.; and aldosterone receptor antagonists, such as spironolactone. The above three types of drugs (beta-blockers + angiotensin converting enzyme inhibitors or angiotensin receptor antagonists + aldosterone receptor antagonists) are known as the “golden triangle” for the treatment of heart failure, and should be taken by patients with enlarged hearts accompanied by heart failure. It should be taken for a long time under the guidance of a doctor. Some patients may also need to add diuretics and other drugs. For patients with simple enlarged heart without heart failure, treatment for the previously mentioned causes is quite important, such as enlarged heart caused by heavy alcohol consumption, which can be restored to normal in some people after stopping alcohol consumption. In addition, some patients may require beta-blockers, angiotensin-converting enzyme inhibitors, or angiotensin receptor antagonists. Some “cardiomegaly” refers to enlargement of the atria, mainly in patients with hypertension, atrial fibrillation, heart failure, and heart valve disease. Therefore, “cardiomegaly” includes both “ventricular hypertrophy” and “heart enlargement”. A detailed examination including ECG, chest X-ray and echocardiogram is required to determine whether the heart is enlarged, ventricular hypertrophy or atrial enlargement. The treatment will then be tailored to the cause. In general, “cardiac hypertrophy” means that the heart has developed organic lesions, and the risk of heart failure and sudden cardiac death is already higher than normal, so it is most important to carry out standardized long-term treatment instead of believing in certain prescriptions. However, there is no need to be overly nervous, as some patients can have their hearts restored to normal after effective treatment.