Shoulder pain is considered to be caused by shoulder strain, frozen shoulder, cervical spondylosis, etc., and should be consulted in time. 1. Shoulder strain: after a lot of shoulder or strenuous exercise, the accumulation of lactic acid in shoulder muscles can cause pain in both shoulders, and shoulder strain caused by prolonged exertion can also cause pain in both shoulders. 2. Frozen shoulder: the presence of aseptic inflammation in the shoulder can limit shoulder movement, tissue adhesion, and the phenomenon of shoulder pain. 3. Cervical spondylosis: when the cervical disc protrudes to the back side, it will compress the nerves or nerve roots in the spinal canal, and the brachial plexus nerves emanating from the cervical region can not exercise the function of innervating the sensation and movement of the shoulder, thus causing pain in both shoulders. If the pain is not relieved by resting, it is necessary to consult a doctor in time for a clear diagnosis and treatment.