Arm creaking may be a normal phenomenon, degenerative osteoarthritis, joint instability and other conditions. 1. Normal phenomenon: the cartilage, synovium and other soft tissues in the joint cavity can appear when they rub against each other, and if there is no other discomfort, then it is considered a physiological sound, which is a normal phenomenon. 2. Degenerative osteoarthritis: when there is degenerative osteoarthritis in the elbow joint, shoulder joint and other parts of the elbow joint, it will be due to the wear and tear of the cartilage of the articular surface, resulting in the direct contact of the bone surface, and there will be a creaking sound of the arm, accompanied by pain, activity limitation and other symptoms. 3. Joint instability: If there is congenital instability or habitual dislocation of the shoulder joint, the instability of the joint position can lead to arm creaking, accompanied by pain. Arm creaking may be related to a variety of reasons, it is recommended to go to the hospital in a timely manner, improve the relevant examination for active treatment.