The causes of hand swelling at night include physiological causes (such as poor posture) and pathological causes (such as hand diseases, etc.). 1. Physiological reasons: such as sleeping posture is not right, long time compression of the hand; or hands for a long time in a fixed position, etc., may cause local blood circulation is poor, and caused by hand swelling, numbness and so on. 2.Hand Diseases (1) Hypertrophic arthritis of the hand: as a subtype of hypertrophic arthritis, it usually starts rapidly and manifests as redness, swelling, distension and pain. (2) Elbow canal syndrome: the ulnar side of the hand innervated by the ulnar nerve and one and a half fingers on the ulnar side of the hand have decreased sensation, or numbness and swelling. (3) Carpal Tunnel Syndrome: Numbness, swelling and pain in the median nerve innervated fingers, thumb and middle finger, with the middle finger being the most prominent. The numbness and swelling are more significant at night and may radiate to the forearm and shoulder. (4) Arterial spasm of the limbs: it starts from the end of the finger, develops towards the root of the finger, and generally does not go beyond the wrist. During the attack, the fingers, palms, cold, accompanied by numbness, pins and needles feeling, finger bending will feel suffocation, flexion and extension unfavorable. In addition to the above reasons, rheumatoid arthritis, rheumatoid arthritis, cervical spondylosis, etc., may cause numbness in the hands. It is recommended to go to the hospital in a timely manner to improve the examination, clarify the cause of the disease and give targeted treatment.