Shoulder pain can be caused by physiological factors such as overwork, maintaining a posture for a long time, or it can be caused by other reasons such as frozen shoulder, myofasciitis, and muscle strain. 1. Physiological factors: If both shoulders perform heavy physical labor, it will lead to shoulder strain, which will lead to the accumulation of lactic acid in the local muscles, which will lead to shoulder pain. In addition, both shoulders maintain a fixed position for a long time, which will lead to local blood circulation obstacles, and will also appear on both sides of the shoulder pain. 2. Frozen shoulder: the cause of frozen shoulder is not yet clear, and it is considered to be caused by shoulder injury, soft tissue degeneration, joint capsule fibrosis and other factors. Patients will have shoulder pain, shoulder stiffness, limited shoulder joint movement and other manifestations, so patients will have symptoms of shoulder pain on both sides. 3. Myofasciitis: the etiology of myofasciitis is not clear, it may be caused by myofascial strain. Patients will have localized muscle persistent soreness and pain, muscle tension, restricted movement and other symptoms, so patients with myofasciitis on both shoulders will also have shoulder pain. 4. Other: patients with shoulder pain on both sides of the shoulder is also considered to be muscle strain, cervical spondylosis and other diseases. If the shoulder pain is caused by physiological factors, there is no need for treatment. If the shoulder pain is caused by diseases, you need to consult a doctor in time, and take appropriate measures to treat it according to the doctor’s instructions.