How is it that mitral stenosis causes dyspnea?

Mitral stenosis: Ms is like a door that doen't open enough to let the blood out of the lungs. This engorgemnt of the lungs causes increased work of breathing and decreased oxygen exchange.

Depends on severity: If severe, mitral stenosis can cause pulmonary edema or fluid buildup in the lung tissue and air spaces as a result of increasing left atrial pressure and pulmonary venous congestion. This may led to shortness of breath as well as crackles on exam.