hi. noted history of swollen arm and trauma. it is best if you consult with a doctor, preferably an orthopedic or a general surgeon, for physical examination and clinical evaluation, especially if the swelling and pain are persistent. if it s just an inflammatory reaction, the swelling will eventually subside in a few days time. fractures must also be ruled-out. diagnostics, such as xray, will be requested for further investigation. management (medical and/or surgical if indications are found) will be directed accordingly. cold compress and pain relievers may help alleviate the symptoms for now. hope this helps. good day!! ~dr.kaye