Rheumatic heart disease accounts for a high percentage of acquired heart disease. How does it cause? Rheumatic heart disease, a chronic heart valve lesion caused by rheumatic fever, is one of the symptoms of rheumatic disease. Rheumatic fever is associated with hemolytic streptococcal infection, an autoimmune disease that results from a metabolic reaction to infection by group A, type B hemolytic streptococci. In addition, viral infections, genetic factors and immune function may also be related to the development of rheumatic fever. Wang Tao, Department of Cardiac Surgery, Qilu Hospital, Shandong University Rheumatic fever has a high incidence in children and adolescents, and is more common between the ages of 5 and 15. The early history of streptococcal infection such as scarlet fever, upper respiratory tract infection, acute purulent tonsillitis, acute pharyngitis, otitis media, lymphadenitis, etc. After 1-4 weeks, fever, excessive sweating, fatigue, panic, pallor, loss of appetite, wandering arthralgia, subcutaneous nodules or subcutaneous erythema, chorea, etc., may further involve the heart and myocarditis. Rheumatic fever is a chronic disease that tends to recur. Therefore, early diagnosis and thorough treatment of pediatric rheumatic heart disease are essential. What should be done to prevent it? Since the direct cause of rheumatic heart disease is rheumatic fever, effective prevention of rheumatic heart disease requires prevention of the occurrence and development of rheumatic fever. The main preventive measures are: 1, improve the standard of living, improve the living environment, avoid cold, humidity, strain and hunger; improve the work and production environment; reduce labor intensity; strengthen physical exercise to enhance the body’s resistance; eat on time, strengthen nutrition, enhance the body’s nutrition and strengthen the strength to resist diseases; 2, actively treat colds, tonsillitis, pharyngitis, otitis media, scarlet fever, upper respiratory tract infections, etc., and avoid strong physical labor infections, etc. Avoid strong physical work to avoid aggravating the condition. Tonsillectomy can be done if necessary. 3, repeated episodes of rheumatic fever activity can be injected with long-acting penicillin star benzathine to prevent streptococcal infection. Penicillin allergy or unwilling to inject penicillin can be oral erythromycin, etc. Prophylaxis should be given to pediatric patients for a minimum of 18 years and to adult patients for a minimum of 5 years. For patients with high susceptibility factors such as cold and damp, repeated recurrence of rheumatic fever and rheumatic valve disease, the duration of prophylaxis should be extended as long as possible, even for life.