Pain in the arm for no reason can be registered orthopedics, rheumatology and immunology, chest pain center and so on. 1. Orthopedics: arm pain for no reason, accompanied by numbness and other symptoms, may be due to cervical spondylosis, thoracic outlet syndrome, elbow syndrome and other causes, these are orthopedic diagnosis and treatment scope. 2. Rheumatology and Immunology: Rheumatologic and immunologic diseases can also cause arm pain, such as rheumatoid arthritis, systemic lupus erythematosus, etc. These diseases need to see the rheumatology and immunology department. 3. Chest pain center: such as acute myocardial infarction, etc., will cause arm tugging pain, but also pressure pain in the anterior region of the heart, which need to hang up the chest pain center. If there is no chest pain center, you can also hang up the emergency medicine or cardiology consultation. There are many reasons for unprovoked arm pain, so you can go to the hospital to consult the pre-screening and triage department to be judged by the medical staff according to the specific condition, so as not to delay the condition.