The mitral valve is a crucial structure in the left ventricle that directs blood from the atrium to the ventricle. When there is mitral valve insufficiency, the blood that should be pumped from the ventricle into the aorta and distributed throughout the body can flow back into the left atrium through the mitral valve. This can sometimes increase the ineffective efforts of the heart, leading to a higher cardiac load, and may sometimes result in heart failure. Generally speaking, there is a limit to how much load the left heart can compensate for. Mild mitral valve insufficiency is mostly within the compensatory range of the heart and may not require treatment. However, it is important to determine the cause of the mitral valve insufficiency, such as whether it is due to cardiac enlargement, poor coronary artery blood supply leading to poor mitral valve development, age-related degenerative changes, rheumatic heart valve disease, or endocardial infection. Some conditions, such as those caused by infection or coronary artery ischemia, need timely treatment. The notion that treatment is not necessary is incomplete. For some age-related degenerative changes, treatment may not be needed.