The numbness of one side of the hand is always considered in the following aspects: 1, if it is mainly to the ulnar side of the palm, the numbness of the ring finger of the little finger or the numbness of the dorsum of the hand of the ring finger of the little finger, it is considered that the patient may have ulnar nerve injury, such as poor sleeping posture, wrist fracture or hand fracture compression of ulnar nerve after the numbness caused by the 2, if it is to the palmar big pisces of the palm or the numbness of the skin of the back of the hand of the thumb, forefinger and middle finger, it is considered that it may be the existence of the radial nerve 3, it may also appear finger numbness, the more common can also have carpal tunnel syndrome or often use the elbow to lift heavy objects after the compression of the radial nerve can also cause numbness on one side of the hand.