Arm pain and weak lifting may be due to strenuous exercise, fatigue and other physiological factors, may also be due to trauma, cervical spondylosis, frozen shoulder and other pathological factors. 1. Physiological factors: due to strenuous exercise or carrying heavy objects and other factors, resulting in arm fatigue, the accumulation of lactic acid in the body, the symptoms of arm pain and weakness can not be lifted up, no treatment is needed, proper rest will gradually ease. 2. Trauma: the shoulder joint consists of four muscles that make up the rotator cuff, which constrains the head of humerus like a sleeve. When the shoulder is impacted by external force or the activity is too strong, it can lead to dislocation of the shoulder joint or rotator cuff injury, which can cause arm pain and weakness. 3. Cervical spondylosis: If the patient suffers from cervical spondylosis, the herniated cervical disc compresses the nerve root, which will lead to arm pain and weakness, and there will also be numbness in the upper limbs. 4. Frozen shoulder: also known as periarthritis of the shoulder joint, when frozen shoulder is attacked, it is easy to lead to adhesion of local tissues, which will lead to arm pain and weakness to lift up, accompanied by symptoms of shoulder joint activity limitation. There are many other causes of arm pain and weakness, if you do not get relief after resting, it is recommended that patients consult the hospital in time to clarify the cause of the disease for treatment, so as not to delay the condition.