Upper arm pain may be caused by overwork, tendonitis, osteomyelitis, frozen shoulder, cervical spondylosis and so on. 1. Overwork: If the patient suffers from trauma or cold lack of exercise, as well as overwork, it will produce upper arm soreness, mainly due to muscle fatigue, lactic acid accumulation. 2. Tendonitis: if the patient is suddenly injured or long time repetitive motion, excessive use of muscle fibers, repeated strong pull resulting in degeneration of tendon collagen fibers, resulting in patients with upper arm pain. 3. Osteomyelitis: If the patient’s bones are infected by various types of bacteria, usually the infection pathway is mainly divided into traumatic, spreading, blood-borne and so on, resulting in the patient’s upper arm pain, accompanied by redness, swelling, high fever and other symptoms. 4. Frozen shoulder: when the shoulder joint and the surrounding soft tissues have degenerative changes, long-term over-activity or poor posture, resulting in patients with upper arm pain. 5. Cervical spondylosis: when the cervical intervertebral disc degenerative changes, resulting in the soft tissues of the neck and the static force balance imbalance, resulting in ligament calcification, osteophytes, so that the patient appeared in the case of upper arm pain. It is recommended to go to the hospital in time, under the diagnosis of the doctor, according to the condition of targeted treatment.