Alternate Names : Median nerve dysfunction, Median nerve entrapment
Carpal tunnel syndrome is pressure on the median nerve — the nerve in the wrist that supplies feeling and movement to parts of the hand. It can lead to numbness, tingling, weakness, or muscle damage in the hand and fingers.
See also: Carpal tunnel release
Overview, Causes, & Risk Factors
The median nerve provides feeling and movement to the “thumb side” of the hand (the palm, thumb, index finger, middle finger, and thumb side of the ring finger).
The area in your wrist where the nerve enters the hand is called the carpal tunnel. This tunnel is normally narrow, so any swelling can pinch the nerve and cause pain, numbness, tingling or weakness. This is called carpal tunnel syndrome.
Carpal tunnel syndrome is common in people who perform repetitive motions of the hand and wrist. Typing on a computer keyboard is probably the most common cuase of carpal tunnel. Other causes include:
- Assembly line work
- Use of tools (especially hand tools or tools that vibrate)
- Sports such as racquetball or handball
- Playing some musical instruments
The condition occurs most often in people 30 to 60 years old, and is more common in women than men.
A number of medical problems are associated with carpal tunnel syndrome, including:
- Bone fractures and arthritis of the wrist
- High blood pressure
- Kidney failure and dialysis
- Menopause, premenstrual syndrome (PMS), and pregnancy
- Rheumatoid arthritis, systemic lupus erythematosus (SLE), and scleroderma
Pictures & Images
Carpal tunnel syndrome
Carpal tunnel syndrome is becoming more frequently recognized and may be occurring more often. It may result from repetitive motion or the use of devices like computer keyboards. It affects the median nerve, the nerve that supplies feeling and movement to the thumb and “thumb-side” of the hand.
Surface anatomy – normal wrist
This picture shows a normal flexed hand. The tendons that move the fingers and are associated with carpal tunnel syndrome are visible just below the wrist.
Compression of the median nerve
A diagnosis of carpal tunnel syndrome may follow testing the affected hand for numbness, tingling, weakness and/or pain in specific areas. Muscle and nerve conduction tests may also help affirm or rule out carpal tunnel syndrome.
Carpal tunnel surgical procedure
In treating carpal tunnel syndrome, surgery may be required to release the compressed median nerve. The open release procedure involves simply cutting the transverse carpal ligament.
Review Date : 10/10/2009
Reviewed By : C. Benjamin Ma, MD, Assistant Professor, Chief, Sports Medicine and Shoulder Service, UCSF Dept. of Orthopaedic Surgery. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.