There are several possible causes of numbness in the index fingertips: first, the most common cause is due to neurogenic cervical spondylosis, which may lead to numbness in the index fingertips due to the protrusion of the cervical disc to the posterior lateral side or the hyperplasia of the cervical bone to the posterior lateral side, which stimulates the nerve roots. The second, more common cause is due to peripheral neuritis, which is a sterile inflammation of the intrinsic nerve of the finger, thus triggering numbness in the tip of the index finger. The third, more common cause is due to various sharp injuries and blunt contusions. Sharp injuries can very easily injure the nerves of the index finger, causing numbness in the fingertip, and blunt contusions can also cause numbness in the fingertip.