Frequent swelling of the feet consider lower extremity venous thrombosis, synovitis, rheumatoid arthritis, kidney disease, heart disease, hypoproteinemia and other causes. 1. Lower extremity venous thrombosis: mainly due to blood clots blocking the venous blood vessels of the lower extremities, blood reflux obstacles, swelling of the lower extremities. 2. Synovitis: Ankle synovitis can cause swelling of the ankle and foot, especially when walking, the swelling is obvious and accompanied by pain. 3. Rheumatoid arthritis: symmetrical swelling of joints, joint deformation, morning stiffness. 4. Kidney diseases: such as nephrotic syndrome, nephritis, renal insufficiency can cause swelling of both lower limbs and proteinuria. 5. Cardiac insufficiency: most of them have a history of heart disease, with panic, shortness of breath and swelling of feet. 6. Hypoproteinemia: when protein intake is insufficient or lost, swelling of the feet can occur. After supplementing protein, it will be better. The cause of frequent swelling of the feet is complex, need to go to the hospital to check the cause of further treatment.