Left shoulder pain may be caused by trauma, frozen shoulder, cervical spondylosis, etc., and you should consult a doctor in time to find out the cause. 1. Trauma: If the left shoulder joint is strained during exercise, or direct violence leads to fracture and dislocation of the left shoulder joint, it can lead to symptoms of pain in the left shoulder joint. At the same time, it may be accompanied by elastic fixation, fracture deformity, shoulder weakness and other manifestations. 2. Frozen shoulder: the etiology and pathogenesis of frozen shoulder is not completely clear, it is generally believed to be a combination of synovitis and joint capsule fibrosis, which leads to adhesion and stiffness around the left shoulder joint, resulting in pain around the left shoulder joint and symptoms of limited activities. 3. Cervical spondylosis: The cervical spine is located between the head, chest, and upper limbs, and is the segment with the smallest volume, the greatest flexibility, the highest frequency of activity, and the greater load. Due to various loads, strain and even trauma, it is easy to degenerate. When cervical spondylosis compresses the nerve root, it can radiate to the left shoulder joint, causing pain in the left shoulder joint and can be accompanied by spasm and tension of the muscles around the left shoulder joint. There may be other reasons for left shoulder pain, so you should consult a doctor in time to clarify the specific cause and get appropriate treatment if necessary.