Pain a week after the arm touched delayed tissue injury, local hematoma, local inflammatory reaction, excessive activity and other causes. 1. Delayed tissue damage: delayed tissue damage occurs in some tissues after injury, especially bone microinjury, which can be aggravated by patient’s activities, causing humerus and other fractures, stimulating the surrounding tissues and causing patient’s pain, 2. Local hematoma: trauma caused by local vascular injury, but not completely broken, continuous blood seepage, more than the absorption limit, can form a local hematoma, thus causing pain symptoms appeared a week later. 3. Local inflammatory response: post-traumatic edema, inflammatory material exudation, with the prolongation of time, can not be fully metabolized inflammatory material accumulation to stimulate the body to produce a perverse reaction, the patient can appear after a week after the arm touched the pain. 4. Excessive activities: due to the lack of systematic treatment after the injury, sports activities, patients with tissue damage aggravation, patients may appear arm touch a week later pain. Patients with arm pain after a week are advised to go to a regular hospital for timely examination, with the help of doctors to clarify the cause of the disease, and targeted treatment or therapy.