Carpal Tunnel Syndrome median nerve neuropathy
The median nerve carries signals to and from the hand.  It passes through a tunnel formed by the carpal bones of the wrist.  If the space in the carpal tunnel becomes too tight, the nerve becomes inflamed.  This causes numbness and tingling in the hand.
Typing and using the computer are frequently blamed for causing carpal tunnel syndrome, although studies have not been able to prove this.  Developing carpal tunnel syndrome may have more to do with the size of the carpal tunnel.  Someone with a naturally smaller carpal tunnel would be more likely to develop carpal tunnel syndrome.
Hand pain, numbness, and tingling gradually increase as carpal tunnel syndrome worsens.  Many people complain of weakness with gripping and begin to drop things.  Symptoms effect the thumb, index finger, middle finger, the palm on the thumb’s side, and part of the ring finger.  This is the portion of the hand innervated by the median nerve.
Carpal tunnel syndrome is diagnosed based on a history, physical exam, and a nerve test called electromyography (EMG) with nerve conduction studies.  Patients usually have a history of gradually increasing pain, numbness, tingling, and weakness in the hand without an associated injury.
During the physical exam, the hand and wrist are inspected for any deformity.  There may be atrophy (wasting away) of the muscles in the palm of the hand.  There may be weakness with grip strength.  The carpal compression test and Phalen’s test involve increasing the pressure over the median nerve at the carpal tunnel.  If this recreates symptoms, carpal tunnel syndrome is suspected.
Carpal tunnel syndrome cannot be identified on x-rays, but they may be obtained to look for other causes of wrist and hand pain.  Because numbness and tingling in the hand can also be causes by pinched nerves in the neck, x-rays of the neck may be obtained as well.
Non-surgical treatments for carpal tunnel syndrome are anti-inflammatory medications like ibuprofen and splinting.  Splints help to prevent prolonged flexion of the wrist to avoid compressing the median nerve.  They are especially helpful when worn at night while sleeping.  Steroid injections can help to reduce pain and inflammation. 
Non-surgical treatment often fails to relieve symptoms associated with carpal tunnel syndrome.  If this is the case, a simple and effective surgery is almost always beneficial.  A carpal tunnel release is performed by cutting the flexor retinaculum to open up the carpal tunnel.  This immediately relieves pressure over the median nerve.  The wrist is stable even with a cut flexor retinaculum.  Strenuous activity with the operative hand must be avoided for a few weeks to allow the incision to heal.
Carpal Tunnel Syndrome
flexor retinaculum (transverse carpal ligament)
median nerve
carpal bones
The flexor retinaculum, or transverse carpal ligament, stretches across the carpal tunnel.  If the space underneath the flexor retinaculum becomes too tight, it compresses and irritates the median nerve. 
During an EMG and nerve conduction studies, electrodes are placed on the arms and hands that evaluate the electrical activity in the nerves.  This can confirm the presence of carpal tunnel syndrome and reveal evidence of other conditions that can cause similar symptoms.