Numbness of the hand at night, may be related to mechanical compression, may also be due to cervical spondylosis, cerebral arteriosclerosis and other causes. 1. Mechanical compression: If you sleep with your hands under your head or on your stomach at night, resulting in prolonged pressure on the upper limbs, it may lead to poor blood circulation in the hands, thus causing numbness of the hands at night. 2. cervical spondylosis: the patient sleeps at night, due to long time to keep the improper sleeping position, easy to lead to the neck muscle stiffness, spasm, the local nerve root compression, which may cause numbness at night, may also be accompanied by dizziness, neck and shoulder pain and other symptoms. 3. Cerebral arteriosclerosis: the wall of the blood vessel is thickened due to fat deposition, resulting in narrowing of the lumen of the blood vessel, slowing down the speed of blood circulation. Coupled with the fact that the body is in a resting state at night, it will make the blood flow even slower, resulting in insufficient blood supply to the brain, which may cause numbness in the hands at night, and may also be accompanied by dizziness, headache and other symptoms. Numbness of the hands at night may also be caused by other reasons, if the symptoms continue to be unable to improve, you should consult a doctor as soon as possible, after a clear diagnosis of the cause, the doctor guided by the treatment.