If the left leg is thicker than the right leg, it is often caused by the following reasons: First, left lower limb swelling: such as varicose veins in the left lower limb or thrombosis, can lead to obvious swelling of the left leg, with venous stasis, the patient will have left lower limb soreness, pain and other discomforts, and after the vascular ultrasonography, it is able to confirm the intravascular lesions. Early treatment through active surgery can make the clinical symptoms get complete relief. Second, right lower limb muscle atrophy: long time walking dysfunction of the right lower limb, such as fracture, dislocation, or muscle long time not dare to bear weight, such as osteoarthritis of the knee joint, ischemic necrosis of the femoral head, will cause obvious atrophy of the right lower limb muscle, the patient will have the right leg obviously become thin. Through muscle exercise and rehabilitation therapy, clinical symptoms can be relieved.