Hand numbness is not a sign of any disease, but it may be caused by a fixed position for a long time, or it may be a symptom of many diseases, such as brain diseases, cervical spondylosis, peripheral nerve diseases, etc.. 1. Physiological factors: if a fixed position for a long time, such as sleeping with a pressed hand or sleeping in a poor posture, resulting in arm pressure, can cause blood flow in the hand, the phenomenon of hand numbness, and reduce the pressure can be relieved by itself. 2. Brain diseases: cerebral infarction, cerebral hemorrhage, transient ischemia and other diseases, or craniocerebral occupational diseases, such as intracranial tumors, metastatic tumors, etc., can affect the cerebral sensory cortex or sensory conduction pathways, resulting in numbness of the limbs, including numbness of the hands, which is mostly seen in the single side. 3. Cervical spondylosis: due to cervical disc herniation, osteophytes and other causes of spinal cord and nerve root compression, numbness of the arm may appear, which may be accompanied by decreased sensation, inactivity and weakness. 3. Peripheral nerve disease: such as diabetes, drug poisoning caused by peripheral nerve damage, the symptoms of hand numbness, usually bilateral, should be regularly monitored blood sugar. If persistent symptoms such as hand numbness, it is recommended to go to the hospital for head, cervical spine and peripheral nerves and other related examinations, to clarify the cause of the disease.