Arm and hand no strength mainly consider the following aspects of the cause: First, if the patient appeared on one side of the arm and hand no strength, and is acute onset of the disease, we should ask the patient whether there is cervical spondylosis, neck trauma or the neck has the feeling of impact, arm, hand numbness, can do cervical spine magnetic resonance examination to understand whether there is cervical spine trauma or cervical disc herniation. Secondly, if the arms and hands are not strong bilaterally, accompanied by numbness of the arms and hands, the patient should be asked whether the symptoms are persistent or paroxysmal, whether there is a tendency to relapse and relieve, whether there is dizziness and lightheadedness, and the need to do cranial and cervical spine magnetic resonance and electromyography to understand whether there is demyelinating disease. Third, if the elderly patients have no strength in their arms and hands, we should ask the patients whether there is any reduction in the strength of the legs, and we need to do a cranial magnetic resonance examination to find out whether there is acute cerebral infarction or cerebral hemorrhage.