Soreness in one shoulder may be caused by physiological reasons such as after strenuous exercise, or it may be caused by pathological factors such as cervical disc herniation, frozen shoulder, shoulder dislocation and so on. 1. Physiological factors: one side of the shoulder strenuous exercise or repeated exercise, such as playing badminton, table tennis, etc., can make a lot of lactic acid accumulation in the shoulder and neck, causing muscle soreness and pain, the symptoms of shoulder pain. 2. Cervical disc herniation: If there is cervical disc herniation, when the herniated disc tissue compresses the cervical nerve root on one side, it can cause pain, numbness and other abnormal sensations on one shoulder. 3. Frozen shoulder: Long-term over-exercise or improper treatment of damaged shoulder joints can cause inflammatory adhesion of the joint capsule of the shoulder joint, resulting in frozen shoulder, which leads to limited pain in the shoulder and restriction of shoulder joint activities. 4. Shoulder dislocation: one side of shoulder dislocation can cause one side of shoulder pain, swelling and limited activities. There may be other reasons for shoulder pain, so it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, and then give targeted treatment or therapy under the guidance of the doctor.