The most common causes of arm soreness are over-exercise, soft tissue injury, cervical spondylosis, humeral epicondylitis, etc. If the symptoms persist, it is recommended to seek medical treatment in time. 1. Excessive exercise: If the patient is engaged in strenuous sports, such as tennis, volleyball, etc., it is easy to lead to the accumulation of lactic acid in the arm, which in turn produces the manifestation of arm soreness. 2. Soft tissue injury: muscle strain, ligament injury, fracture and other conditions in the arm can also cause arm pain, patients usually accompanied by local skin redness and swelling phenomenon. 3. Cervical spondylosis: compression of the cervical intervertebral discs to the nerves can cause numbness and pain in the arms, cervical intervertebral discs continue to be compressed without relief, but also easy to cause arm soreness. 4. Epicondylitis of the humerus: The repeated twisting of the arm by the patient may cause inflammation of the epicondyle of the humerus, which may also cause pain or soreness in the arm. The causes of arm pain are many, may also be associated with congenital absence of the paravalvular bone, tumors and other diseases, it is recommended to go to the hospital in a timely manner, by the doctor to identify the cause of the disease, targeted treatment.