Shoulder rattling may be caused by physiological factors such as joint popping or pathological factors such as frozen shoulder and shoulder joint injury. 1. Physiological factors: Shoulder rattling without other discomforts is mostly physiological rattling, which is related to the gas and tendon friction in the joints, and does not need to be dealt with. 2. Frozen shoulder: long-term cold or sports strain on the shoulder may cause aseptic inflammation, and rattling sound may appear when the shoulder is moving, accompanied by shoulder pain and activity limitation at the same time. 3. Shoulder joint injury: If rotator cuff injury or old fracture occurs in the shoulder joint, it will lead to instability of the shoulder joint activities, as well as the residual fragments of the old fracture, which will cause rattling when the shoulder joint is moving and collision occurs. Shoulder rattling may be caused by other factors, and it is recommended that the patient should consult the hospital in time to find out the cause and then carry out targeted treatment.