The symptoms of patients with myocarditis depend on the extensiveness and location of the lesion and are influenced by many factors. The clinical manifestations of myocarditis vary in severity. Most patients have prodromal symptoms of infection, such as fever, fatigue, muscle aches and other symptoms of upper respiratory tract infection or gastrointestinal symptoms such as nausea, vomiting and diarrhea, 1-3 weeks before the onset of the disease; when the myocardial involvement is extensive, patients mostly feel palpitations and chest tightness, and if the inflammation involves the pleura and pericardium, there is often significant chest pain; severe Myocarditis can lead to cardiogenic shock and sudden death. These patients mostly have dyspnea, edema, or even syncope and sudden death after prodromal symptoms, often due to severe arrhythmias, heart failure, and cardiogenic shock caused by large acute myocardial damage. Depending on the clinical manifestations, myocarditis can be clinically classified as mild, subclinical, insidiously progressive, acute dilated cardiomyopathy, atrioventricular block, cool myocardial infarction, and sudden death. Patients with myocarditis have a variety of clinical manifestations, and thus it is less likely to rely on symptoms alone to diagnose myocarditis. Therefore, if palpitations, chest tightness and chest pain occur after symptoms such as fever, cough, sore throat, weakness, nausea and vomiting, one should be alert to the possibility of myocarditis.