The ulnar nerve is a common culprit for numbness and tingling in the hand. If it's constricted in the wrist area, the pinky side of the hand can become numb and tingly. The thumb and forefinger can lose pinching strength when the muscle between them becomes atrophied as well. These symptoms develop gradually and can be a result of repetitive tasks irritating the nerve (such as typing with bent wrists, jackhammering, and similar actitivites), putting too much prolonged pressure on a bent wrist (such as long bicycle rides), or most often, a small ganglion cyst that develops in the wrist area and puts pressure on the nerve.
This condition is called Ulnar Tunnel Syndrome of the Wrist. It should be properly diagnosed and treated by an orthopedic doctor specializing in hand, wrist, and arm problems. Because the ulnar nerve runs from the neck to the fingers, the doctor will likely examine the elbow as well. Other symptoms he or she may look for during the examination include dry skin between the fingers and tingling in the hand when certain spots are tapped. MRI imaging can show a cyst. X-ray imaging can reveal a bone fragment. Either of these can be blamed for the symptoms. And even if you don't know exactly what's wrong, symptoms that are getting worse are usually worth a trip to the doctor.
Treatment for Ulnar Tunnel Syndrome depends on the cause. Since most cases are caused by a cyst, which must be removed surgically, seeing an experienced, well-trained hand surgeon is recommended. If the condition is brought on by activities, the doctor will likely advise changing them to reduce or eliminate pressure on the nerve. Anti-inflammatory medications, ice, and a period of rest are also common treatments.