There are many reasons for swollen feet in the afternoon, the most common reasons are cardiac reasons and vascular reasons. The cause of the heart is mainly right heart insufficiency, the pump dysfunction of the right heart causes venous blood return obstruction, the blood is easy to return at night when resting, so the foot swelling disappears at night, and the blood is not easy to return to the heart during the daytime activity, causing the foot swelling. Vascular causes are mainly seen in venous thrombosis, poor venous blood return; venous valve insufficiency of lower limbs, causing poor venous blood return; coronary artery bypass surgery to extract the saphenous vein, causing poor venous blood return and other cases.