The causes of shoulder pain may be excessive exercise, muscle strain, frozen shoulder, cervical spondylosis and so on. 1. Excessive exercise: Excessive neck and shoulder exercise, workout or short-time overwork, due to the accumulation of local lactic acid, can cause shoulder pain, which can be relieved after rest. 2. Muscle strain: Bilateral shoulder pain can occur due to muscle strain caused by long-term heavy physical labor. 3. Frozen shoulder: aseptic inflammation around the shoulder joints caused by trauma, chronic strain injury, etc., leading to frozen shoulder, which will cause bilateral shoulder pain and restricted movement. 4. Cervical spondylosis: Degeneration of cervical intervertebral discs compresses or stimulates the nerves innervating the shoulder joints bilaterally, which can also cause bilateral shoulder joint pain, and numbness and limited movement of both shoulders can also occur. Shoulder pain may also have other causes, such as trauma, arthritis, etc., if the rest does not relieve, it is recommended to go to the hospital in a timely manner, improve the relevant examinations, identify the cause of the disease and follow the doctor’s instructions for targeted treatment, so as not to delay the condition.