The symptoms of swelling and pain in the calf are commonly caused by calf muscle strain, fracture or post-surgical rehabilitation, and calf vascular disease, etc., as follows: First, calf muscle strain, mainly related to prolonged standing work or excessive weight-bearing, the patient will experience calf swelling and pain, and the pain symptoms are slightly obvious when pressed, and the symptoms will be relieved after rest. Second, the calf fracture or surgery, the process of rehabilitation, will show the symptoms of calf swelling and pain, mainly caused by temporary disorders of blood circulation, after active rehabilitation and massage therapy, the symptoms will be significantly relieved. Third, calf vascular lesions, such as deep vein thrombosis will lead to calf venous return obstruction, the patient will have swollen limbs, painful symptoms increase when pressed, which can be confirmed through ultrasound examination, and requires surgical treatment to remove the thrombus in order to restore blood circulation and improve the symptoms of calf swelling and pain. It is important to diagnose and treat the swelling and pain in the calf in time so that the symptoms can be relieved as soon as possible.