Mitral valve regurgitation can easily lead to heart failure, especially left heart failure. This is because, when there is moderate or severe mitral regurgitation, the left ventricle contracts, and a large amount of blood in the left ventricle flows back into the left atrium. When the ventricle relaxes and fills again, the volume of blood in the left ventricle significantly increases, leading to an overload in the capacity of the left ventricle. Over time, this causes left ventricular hypertrophy, a decline in the heart's pumping function, and thus, heart failure occurs. In terms of symptoms, it presents as exertional dyspnea and paroxysmal nocturnal dyspnea, among other symptoms. When these symptoms occur, it is necessary to go to the hospital for proper examination and treatment, and to take diuretic medications under the guidance of a doctor to improve the symptoms.