In the case of rheumatic heart disease, it spans different stages of the disease. In its early stage, it can affect the heart valves to a certain extent. However, this impact may progressively worsen over time. Thus, the initial effects on the heart are not severe. Once it causes mitral valve regurgitation, patients often exhibit clear symptoms, such as chest tightness and shortness of breath after activity, and in severe cases, pulmonary edema, coughing, and expectoration of bloody sputum. Severe cases can lead to nocturnal insomnia and orthopnea, presenting with paroxysmal breathing difficulties. These symptoms indicate cardiac function failure, a serious condition. Therefore, inadequate or delayed treatment can be life-threatening.