The reasons why the elderly can not move half of their body include cerebrovascular disease, intracranial malignant tumor, cervical spine disease and so on. 1. Cerebrovascular disease: when cerebrovascular disease including cerebral hemorrhage or cerebral infarction develops, due to the damage of brain tissues, the motor function of half of the limbs will be impaired, which will be manifested as the symptom that half of the body can’t move. 2. Intracranial malignant tumors: when suffering from malignant tumors, due to tumor metastasis and compression, resulting in necrosis of brain cells, and the symptoms of half of the body of the elderly can not move. 3. Cervical spondylosis, for example, when the spinal cord is compressed due to herniated discs or osteophytes, etc., it may also be manifested as the symptoms of the old man who can’t move half of his body. There are many reasons why the elderly half of the body can not move, when this situation occurs, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, to give targeted treatment.