The left bladder mostly refers to the left shoulder joint and upper arm. Cervical spondylosis can cause pain in the left shoulder joint and upper arm, mostly caused by muscle spasm and nerve compression. Cervical spondylosis is caused by poor posture, exposure to cold, improper exercise and other reasons, causing degeneration of the cervical vertebrae, resulting in pressure on the nerves, blood vessels, spinal cord and other tissues, resulting in neck pain, upper extremity pain, numbness of the fingers, dizziness, tinnitus and other symptoms. Because cervical spondylosis is often accompanied by muscle spasm in the neck and nerve root compression in the neck, muscle spasm in the neck can cause pain in the neck and the upper part of the shoulder joint, and nerve compression can cause radiating pain in the upper limbs, which can be radiated from the neck to the shoulder joints, elbow joints and even the fingers, and is often accompanied by numbness, therefore, cervical spondylosis can cause pain in the left shoulder joint and the upper arm. If the pain in the left shoulder joint and upper arm persists without relief, it is recommended to consult a doctor in time and under the guidance of the doctor.