DefinitionCarpal tunnel syndrome is a condition in which there 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.
Alternative NamesMedian nerve dysfunction; Median nerve entrapment
Causes, incidence, and risk factorsThe 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.Some people who develop this problem were born with a carpal tunnel that is small.Many people believe that carpal tunnel syndrome is caused by making the same hand and wrist motion over and over. In fact, using hand tools that vibrate may lead to carpal tunnel. Yet, there are no good studies that prove carpal tunnel is caused by typing on a computer, using a mouse, or repeating movements while working, playing an instrument, or playing sports.Carpal tunnel syndrome occurs most often in people 30 to 60 years old, and is more common in women than men.Other factors that may lead to carpal tunnel syndrome include:Alcohol abuseBone fractures and arthritis of the wristCyst or tumor that grows in the wristInfections ObesityIf your body keeps extra fluids during pregnancy
or menopauseRheumatoid arthritis
SymptomsClumsiness of the hand when gripping objectsNumbness or tingling in the thumb and next two or three fingers of one or both handsNumbness or tingling of the palm of the handPain extending to the elbowPain in the wrist or hand in one or both handsProblems with fine finger movements (coordination) in one or both handsWasting away of the muscle under the thumb (in advanced or long-term cases)Weak grip or difficulty carrying bags (a common complaint)Weakness in one or both hands
Signs and testsDuring a physical examination, the health care provider may find:Numbness in the palm, thumb, index finger, middle finger, and thumb side of the ring fingerWeak hand gripTapping over the median nerve at the wrist may cause pain to shoot from the wrist to the hand (this is called Tinel's sign)Bending the wrist forward all the way for 60 seconds will usually result in numbness, tingling, or weakness (this is called Phalen's test)Tests may include:ElectromyographyNerve conduction velocityWrist x-rays should be done to rule out other problems (such as wrist arthritis)
TreatmentYou may try wearing a splint at night for several weeks. If this does not help, you may need to try wearing the splint during the day. Avoid sleeping on your wrists. Hot and cold compresses may also be recommended.There are many changes you can make in the workplace to reduce the stress on your wrist:Special devices include keyboards, different types of computer mouse, cushioned mouse pads, and keyboard drawers.Someone should review the position you are in when performing your work activities. For example, make sure the keyboard is low enough so that your wrists aren't bent upward while typing. Your health care provider may suggest an occupational therapist.You may also need to make changes in your work duties or recreational activities. Some of the jobs associated with carpal tunnel syndrome include those that involve typing and vibrating tools. Carpal tunnel syndrome has also been linked to professional musicians.MEDICATIONSMedications used in the treatment of carpal tunnel syndrome include nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen or naproxen. Corticosteroid injections, given into the carpal tunnel area, may relieve symptoms for a period of time.SURGERYCarpal tunnel release is a surgical procedure that cuts into the ligament that is pressing on the nerve. Surgery is successful most of the time, but it depends on how long the nerve compression has been occurring and its severity.See also: Carpal tunnel release
Expectations (prognosis)Symptoms often improve with treatment, but more than 50% of cases eventually require surgery. Surgery is often successful, but full healing can take months.
ComplicationsIf the condition is treated properly, there are usually no complications. If untreated, the nerve can be damaged, causing permanent weakness, numbness, and tingling.
Calling your health care providerCall for an appointment with your health care provider if:You have symptoms of carpal tunnel syndromeYour symptoms do not respond to regular treatment, such as rest and anti-inflammatory medications, or if there seems to be a loss of muscle in your fingers
PreventionAvoid or reduce the number of repetitive wrist movements whenever possible. Use tools and equipment that are properly designed to reduce the risk of wrist injury.Ergonomic aids, such as split keyboards, keyboard trays, typing pads, and wrist braces, may be used to improve wrist posture during typing. Take frequent breaks when typing and always stop if there is tingling or pain.
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Huisstede BM, Randsdorp MS, Coert Jh, Glerum S, van Middlekoop M, Koes BW. Carpal tunnel syndrome. Part II: effectiveness of surgical treatments -- a systematic review. Arch Phys Med Rehabil. 2010;91:1005-1024.
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