Numbness in the fingers and the hands is usually caused by some type of peripheral neuropathy---a problem with the nerves that carry sensory information to and from the central nervous system. When nerve function is disrupted, the nerves send abnormal signals or delayed signals, which can cause the abnormal sensation of numbness.
Carpal Tunnel Syndrome
The carpal tunnel is a passageway that protects the median nerve, one of the main nerves in the arm. The median nerve runs from the forearm into the hand and controls sensation in part of the hand as well as the muscles that allow the fingers to move. Carpal tunnel syndrome occurs when the carpal tunnel places excess pressure on the nerve. Excess pressure usually occurs as a result of repetitive motion that causes inflammation of the carpal tunnel, but can also occur because of an abnormally narrow carpal tunnel, according to the National Institute of Neurological Disorders and Stroke. Symptoms of carpal tunnel syndrome include numbness and tingling in the fingers and hands, decreased grip strength, a swollen feeling and a burning sensation. Mild cases of carpal tunnel are usually treated with a combination of anti-inflammatory drugs and physical therapy. In severe cases, surgery may be needed to reduce the pressure on the median nerve.
Ulnar Nerve Entrapment
The ulnar nerve is another main nerve in arm that is responsible for sensation in part of the hand and some fine movement. The ulnar nerve extends from the collarbone down the inside of the upper arm, behind the elbow and into the hand. Ulnar nerve entrapment is a condition that occurs when excess pressure is placed on the nerve, compressing it. When the nerve becomes compressed, it can result in numbness in the fingers and hands, pain, weak grip and problems with finger coordination. The nerve most commonly becomes entrapped at the elbow, but may also be compressed at the wrist or collarbone, according to the American Academy of Orthopaedic Surgeons. The exact cause of ulnar nerve entrapment is unknown, but several factors, such as prior elbow fractures, bone spurs and inflammation of the elbow joint, are believed to contribute. Treatment usually consists of immobilization of the arm, over-the-counter pain relievers and anti-inflammatory medications. In severe cases, surgery may be needed to relieve the pressure on the nerve.
Ganglion Cysts
Ganglion cysts are benign fluid-filled lumps that develop along the tendons in the joints of the hands or wrists. The cause of ganglion cyst development is unknown and a cyst may develop gradually or appear suddenly, according to MayoClinic.com. Ganglion cysts can vary in size from very large to miniscule. Size can change with changes in activity level as well. At active times, ganglion cysts will grow and shrink down again during periods of non-activity. If a ganglion cyst exerts pressure on the nerves by the affected joint, it can result in pain, weakness and numbness in the wrist, hands or fingers. Most ganglion cysts require no treatment, however, if symptoms are extremely bothersome there are two treatment options available. Aspiration is a procedure in which fluid is drained from the cyst with a syringe. The cyst may also be completely removed with surgery.
