Left shoulder pain should be alert to the occurrence of soft tissue injury, cervical spondylosis, frozen shoulder and so on. 1. soft tissue injury: due to prolonged engagement in heavy physical labor, or often strenuous exercise generated by some of the injuries, can cause local soft tissue injuries, showing the symptoms of left shoulder pain. 2. cervical spondylosis: if the head is lowered for a long time, it may lead to cervical spine strain for a long time, and if the treatment is not timely, it may also show the condition. 3. Frozen shoulder: mainly due to chronic inflammation of the surrounding ligamentous tissues, resulting in left shoulder pain, which occurs mostly due to long-term overwork, and the pain state is more obvious at night, accompanied by fear of cold, pressure pain, muscle spasm and other clinical symptoms. If left shoulder pain occurs, it is recommended to observe closely, and seek medical attention in time for any abnormalities, and follow the doctor’s instructions for treatment.