Carpal Tunnel: Causes, Symptoms & Diagnosis

Carpal Tunnel

What Is Carpal Tunnel Syndrome?

Carpal tunnel syndrome is the compression of the median nerve as it passes into the hand. The median nerve is located on the palm side of your hand (also called the carpal tunnel). The median nerve provides sensation (ability to feel) to your thumb, index finger, long finger, and part of the ring finger. It supplies the impulse to the muscle going to the thumb. Carpal tunnel syndrome can occur in one or both of your hands.

Swelling inside your wrist causes the compression in carpal tunnel syndrome. It can lead to numbness, weakness, and tingling on the side of your hand near the thumb.

What Causes Carpal Tunnel Syndrome?

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The pain in your carpal tunnel is due to excess pressure in your wrist and on the median nerve. Inflammation can cause swelling. The most common cause of this inflammation is an underlying medical condition that causes swelling in the wrist, and sometimes obstructed blood flow. Some of the most frequent conditions linked with carpal tunnel syndrome are:

  • diabetes
  • thyroid dysfunction
  • fluid retention from pregnancy or menopause
  • high blood pressure
  • autoimmune disorders such as rheumatoid arthritis
  • fractures or trauma to the wrist

Carpal tunnel syndrome can be made worse if the wrist is overextended repeatedly. Repeated motions of your wrist contribute to swelling and compression of the median nerve. Problems include:

  • poor positioning of your wrists while using your keyboard or mouse
  • prolonged exposure to vibrations from using hand tools or power tools
  • any repeated movement that overextends your wrist, such as playing the piano or typing

Who Is at Risk for Carpal Tunnel Syndrome?

Risk Factors

Women are three times more likely to have carpal tunnel syndrome than men. Carpal tunnel syndrome is most frequently diagnosed between the ages of 30 and 60. Certain conditions increase your risk for developing carpal tunnel syndrome, including diabetes, high blood pressure, and arthritis.

Lifestyle factors that may increase the risk for carpal tunnel syndrome include smoking, high salt intake, sedentary lifestyle, and a high body mass index (BMI).

Jobs that involve repetitive wrist movement include manufacturing, assembly line work, keyboarding occupations, and construction work. People employed in these occupations may be at higher risk of developing carpal tunnel syndrome.

What Are the Symptoms of Carpal Tunnel Syndrome?

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The symptoms are usually found along the nerve path because of compression of the median nerve. Your hand may “fall asleep” frequently and drop objects. Other symptoms include:

  • numbness, tingling, and pain in your thumb and first three fingers of your hand
  • pain and burning that travels up your arm
  • wrist pain at night that interferes with sleep
  • weakness in the muscles of the hand

How Is Carpal Tunnel Syndrome Diagnosed?

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Doctors can diagnose carpal tunnel syndrome using a combination of your history, a physical examination, and tests called nerve conduction studies.

A physical examination includes a detailed evaluation of your hand, wrist, shoulder, and neck to check for any other causes of nerve pressure. Your doctor will look at your wrists for signs of tenderness, swelling, and any deformities. He will check sensation to the fingers and strength of the muscles in your hand.

Nerve conduction studies are diagnostic tests that can measure the conduction speed of your nerve impulses. If the nerve impulse is slower than normal as the nerve passes into the hand, you may have carpal tunnel syndrome.

How Is Carpal Tunnel Syndrome Treated?

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Treatment of carpal tunnel syndrome depends on how severe your pain and symptoms are and if there is weakness. In 2008, the Academy of Orthopaedic Surgeons released guidelines for the effective treatment of carpal tunnel. The recommendation was to try to manage carpal tunnel pain without surgery, if possible.

Nonsurgical options include:

  • avoiding positions that overextend your wrist
  • wrist splints that hold your hand in a neutral position, especially at night
  • mild pain medication and medications to reduce inflammation
  • treatment of any underlying conditions you may have, such as diabetes or arthritis
  • steroid injections into your carpal tunnel area to reduce inflammation

Surgery may be necessary if there’s severe damage to your median nerve. Surgery for carpal tunnel syndrome involves cutting the band of tissue in the wrist that crosses the median nerve so as to lessen the pressure on your nerve. Factors that determine success or failure are age of the patient, duration of symptoms, diabetes mellitus, and if there is weakness (which usually is a late sign). The outcome is usually good.

How Can I Prevent Carpal Tunnel Syndrome?

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Paying careful attention to hand posture and avoiding activities that overextend your wrist are also important strategies to reduce symptoms. Exercises done in physical therapy may also be helpful.

What Is the Long-Term Outlook?

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Treating your carpal tunnel syndrome early with physical therapy and lifestyle changes can lead to significant long-term improvement and eliminate symptoms.

Untreated carpal tunnel syndrome can lead to permanent nerve damage, disability, and loss of hand function.

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