Shoulder pain after walking for a long time may be due to cold stimulation, strain injury, frozen shoulder, cervical spondylosis and heart disease. 1. Cold stimulation: cold shoulder will increase muscle excitability and muscle contraction will cause pain. 2. Strain injury: overloading of the shoulder due to carrying heavy objects, playing computer, etc., resulting in damage to soft tissues such as muscles or ligaments. Walking for a long time involves the damaged part of the shoulder, triggering pain, soreness and swelling. 3. Frozen shoulder: refers to the inflammation caused by chronic injury, soft tissue degeneration, etc., which manifests itself as shoulder pain, inconvenience in arm extension, stiffness, and so on. 4. Cervical spondylosis: caused by degeneration of cervical vertebrae and long-term strain injury, prolonged walking will aggravate the pressure of cervical vertebrae on the soft tissues of the shoulder, which will lead to pain, dizziness and stiffness of the neck. 5. Heart disease: including myocardial infarction, myocardial ischemia, etc. Walking for a long time leads to insufficient blood supply to the heart, which is typically manifested as pain in the left shoulder accompanied by palpitations, chest tightness, chest pain and other symptoms. Shoulder pain alone can not accurately determine the cause, if the pain persists or worsens after rest, it is recommended to go to the hospital in a timely manner, with the help of a doctor to clarify the cause of the disease and targeted treatment or therapy.