Mitral and tricuspid regurgitation can cause swelling of the lower extremities. 1. Mitral regurgitation: In severe mitral regurgitation, the volume of cardiac output decreases, the heart rate accelerates, blood stasis occurs in the pulmonary veins, causing left heart failure, followed by right heart failure in the late stage, and the blood stasis occurs in the venous system of the body circulation, causing dilatation of the veins of the lower limbs and edema of the lower limbs, i.e. cardiogenic edema. 2. Tricuspid valve edema: when tricuspid valve regurgitation, the blood discharge of the right heart decreases, the pressure of the upper and lower vena cava rises, and the blood stagnates in the venous system, causing cardiogenic edema. If you find the symptoms of lower limb edema, there may be kidney disease, lower limb deep vein thrombosis and other diseases, may also be caused by valve regurgitation, you should go to the hospital in time, can not be ignored, so as not to aggravate the condition.