There are many reasons for the numbness of the index finger, which are generally considered to be caused by cervical spondylosis, carpal tunnel syndrome, cerebrovascular disease, endocrine metabolic disorders and other reasons. 1. Cervical spondylosis: due to the herniation or bulging of cervical intervertebral discs that compress the nerves, numbness of the fingers can occur, accompanied by dizziness, neck and shoulder discomfort and other symptoms. 2. Carpal Tunnel Syndrome: due to the compression of the median nerve, numbness of the index finger can occur, accompanied by dysfunction and other symptoms. 3. Cerebrovascular disease: when patients suffer from cerebral infarction, cerebral hemorrhage and other diseases, numbness of the fingers can occur along with dizziness, headache and other symptoms. Most of them are caused by cerebral arteriosclerosis due to long-term high blood pressure and high blood fat. 4. Endocrine metabolic disorders: usually seen in diabetes, diabetes due to poor blood sugar control can cause peripheral neuropathy, numbness of the fingers and toes and accompanied by sock-like changes. In addition to the above diseases, there are many other causes can lead to numbness of the index finger, it is recommended that patients go to the hospital in a timely manner, to clarify the cause of the disease for targeted treatment.