Myocarditis is an inflammatory disease of the heart muscle. The severity of patients with myocarditis depends on the extensiveness of the lesion, with its location, and is influenced by many factors. Myocarditis is a type of disease that occurs when various factors cause damage to the myocardium, with myocardial inflammation as the main manifestation, and is most commonly caused by viral infections, i.e. viral myocarditis. The clinical manifestations of myocarditis vary in severity. In mild cases, the symptoms are mild or almost asymptomatic. Most patients have prodromal symptoms of infection such as fever, fatigue, muscle aches or gastrointestinal symptoms such as nausea and vomiting 1-3 weeks before the onset of the disease; when the myocardial involvement is more extensive, patients may have palpitations, chest tightness, and often chest pain if the inflammation involves the pleura and pericardium; severe myocarditis can lead to cardiogenic shock and sudden death, often due to massive acute Myocardial damage. The severity of myocarditis is influenced by the extensiveness of the myocardial lesion, the site of the lesion, the body’s response, previous cardiac function status, and the type of virus that infected the heart. Myocarditis is often an inflammatory damage to the myocardium caused by infection and other factors, most commonly viral myocarditis. The severity of myocarditis is related to a number of factors, and some patients are asymptomatic, but some patients present with severe conditions. If you develop palpitations, chest tightness, or chest pain when you have a cold or fever, you must pay attention and seek medical attention promptly.