Generalities:

The human heart is composed of cavities, two atria in the upper part that receive blood; and two venticles at the bottom that pump blood to the lungs (right side) and to the rest of the body (left side). For the cardiovascular system to function optimally, allowing good oxygenation of the entire body, it is necessary for the blood to flow in the correct direction, for which there are a series of valves. The mitral valve is one of the most important as it separates the atrium from the venticle on the left side of the heart. When it functions poorly, a percentage of the blood returns to the atrium at the time of systole (contraction of the heart). This causes poor blood flow, as well as an overexertion of the heart muscle, which can eventually affect the heart.
Mitral valve disease can present as:

A visit to a cardiologist is necessary if the symptoms do not subside.