If a patient has pain in the small arm, the causes include epicondylitis of the humerus, radial stem stenosis tenosynovitis, osteofasciitis, injury, etc., as follows: i. Epicondylitis of the humerus or with radial stem stenosis tenosynovitis: such patients are prone to have painful symptoms in the small arm area of the arm. Second, osteofasciitis: osteofasciitis in the small arm area, also prone to arm pain in the small arm. Injury: Injury in the small arm area can also lead to swelling, pain and limited movement in the small arm area. Therefore, after a patient has arm pain, it is important to consult a doctor to see what causes it and treat the cause to relieve the pain symptoms. In case of arm pain, it is important to avoid forearm rotation and excessive force activities on the upper limb to avoid aggravating the pain.