Numbness of the index finger and thumb of the left hand is mainly due to the following reasons: 1) cervical spondylosis, such as in the presence of cervical disc herniation, compression of the nerves can easily appear numbness of the left thumb and forefinger. 2) Carpal tunnel syndrome, such as in the long term repeated rubbing of the clothes with the hand or hand holding the mouse, or long term hand activities can easily lead to carpal tunnel syndrome, the compression of the median nerve causes numbness of the left hand. 3) numbness of the left index finger and thumb, we should ask the patient whether there is a history of trauma, fracture, and if there are gloves to fix the wrist movement, the symptoms may be relieved. Numbness of the index finger and thumb can be relieved by giving gloves to fix the wrist movement.3. Numbness of the index finger and thumb of the left hand, ask the patient whether there is a history of trauma or fracture, if there is a fracture of the wrist, it can also cause numbness of the index finger of the left hand after nerve injury.