The causes of left arm pain are many, as follows: First, strain disease: long time chronic strain leads to chronic injury to the arm part of the myofascia, or produce aseptic inflammation, can lead to the left arm there are obvious symptoms of pain, such as the presence of humerus epicondylitis, humerus epicondylitis and so on. Second, strenuous exercise: the patient’s recent period of strenuous exercise, resulting in local muscle strain, the body’s creatine kinase secretion is too high, will lead to the patient’s local presence of obvious symptoms of pain. Third, cervical spine disease: cervical spine disease will stimulate and compress the nerves, which will lead to the patient’s left arm with obvious symptoms of pain. Fourth, degenerative joint changes: can be seen in the arm degenerative lesions, such as the presence of osteoarthritis, etc., will also lead to the existence of the clinical symptoms of left arm pain.