Arm pain is considered to be caused by muscle strain, cervical spondylosis, rheumatoid arthritis and other conditions. 1. Muscle strain: this disease is mainly due to the patient’s recent frequent physical labor or strength exercise, resulting in excessive contraction and stretching of local muscles, beyond their capacity, causing muscle tear. Patients often appear in the affected area of sudden pain, muscle pain, muscle spasm and other symptoms, if the patient recently often pull heavy objects, push dumbbells and other actions, causing muscle strain in the arm, will be manifested as arm pain. 2. Cervical spondylosis: this disease is more common in the clinic, usually due to degenerative changes in the cervical spine of patients, or the existence of poor sleeping posture, poor work habits, cervical spine developmental abnormalities and other conditions. Patients with this disease often appear neck muscle stiffness, pain and other symptoms, with the development of the disease, the pain can be radiated to the upper limbs, resulting in arm pain. 3. Rheumatoid arthritis: this disease is an autoimmune disease, the specific cause is still unclear, clinical considerations and genetic factors, autoimmune system abnormalities, infections and other factors. The disease occurs in the patient’s wrists, knees, elbows and other joints, often leading to joint swelling, pain and other symptoms, when the disease attacked in the elbow, the patient will appear the symptoms of arm pain. There are many causes of arm pain, so it is recommended that patients seek medical attention to clarify the cause of the disease before treatment.