The most common thing that happens when the arm is swollen is the painful swelling due to local soft tissue trauma. This condition can be given an ice pack immediately if it has just started to happen, and can be applied externally with ice cubes or with an ice and water mixture. It is best to apply a layer of cotton cloth on the skin surface to avoid frostbite because it is too cold. And after 24 hours after the injury, you can do the following treatment: First, you can local hot compress, can promote local blood circulation, speed up the local swelling of the subside. Second, can be applied externally to reduce swelling and pain, blood circulation and blood stasis ointment. Third, you can also do some local physical therapy, commonly used is infrared therapy, microwave therapy or medium frequency pulse electric therapy. In addition, it must be noted that if the local swelling and pain are accompanied by local deformity or functional limitation of activities, the possibility of fracture is highly suspected, and it is necessary to go to the hospital to take X-rays for examination to exclude the problem of fracture.