The arm can not be lifted up to consider physiological factors, pathological factors such as cervical spondylosis, rotator cuff injury, cerebrovascular disease and so on. 1. Physiological factors: if you sleep at night when the upper limb compression for a long time caused by local blood circulation is not good, if you often work in a position that will cause muscle fatigue, the arm can not be lifted up, can be reduced through rest. 2. Cervical spondylosis: osteophytes or herniated intervertebral discs can cause sensory and motor disorders in the upper limbs, and the arms can not be lifted, accompanied by the symptoms of numbness. 3. Rotator cuff injury: Trauma to the shoulder joint can cause rupture of the supraspinatus muscle, causing shoulder pain and inability to lift the arm. It can be clearly diagnosed through shoulder MRI and other examinations. 4. Cerebrovascular disease: for example, cerebral infarction and cerebral hemorrhage can cause unfavorable limb movement, which can be clearly diagnosed through cranial CT or cranial MRI. All, the arm can not be lifted up need to go to the hospital in time to check and clarify the cause of further treatment.