The most common reason for middle and index finger numbness is carpal tunnel, which means the median nerve in the wrist and hand has an injury, according to About.com. Pain and weakness in the hand and wrist are other symptoms of carpal tunnel.
In patients with carpal tunnel, numbness and tingling typically only occur in half of the ring finger, the thumb, index and middle fingers, explains About.com. The pinkie finger does not go numb with this condition. Most of the time, the symptoms are worse at night, and patients may find relief by shaking the hands. Pain is common with carpal tunnel. Many people not only have pain in the hand and fingers, but it often radiates down to the wrist and forearm.
The nerves in the hand, including the median nerve, send messages to the brain about pain, feelings and when to contract the muscles, states About.com. When people have severe carpal tunnel, this nerve causes the muscle to feel weak, and this is difficult to treat. There are several tests that a doctor may choose to do in order to diagnose carpal tunnel, and there are ways to treat the symptoms of the condition. Surgery is the best way to treat carpal tunnel for the long term, but it is important to contact a surgeon who is familiar with the procedure.