Definition | Causes | Risk Factors | Symptoms | Diagnosis | Treatment | Prevention

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Definition

Carpal tunnel syndrome is a nerve disorder of the hand. It is caused by compression of the median nerve. The median nerve gets squeezed inside a narrow passage in the wrist called the carpal tunnel. This nerve provides feeling to the thumb, index and middle fingers, and half the ring finger.

Carpal Tunnel Syndrome

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Causes

Carpal tunnel syndrome is created by pressure on the median nerve. This pressure is caused by the carpal tunnel becoming narrower. The narrowing can be caused by many factors, including:

  • Swelling of tissue in the carpal tunnel due to injury or fluid changes in your body
  • Hereditary narrow carpal tunnel
  • Tumors (rare)

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition.

Risk factors for carpal tunnel syndrome include:

Symptoms

Carpal tunnel syndrome causes symptoms in one or both hands or wrists. Symptoms may include:

  • Tingling, burning, or numbness, especially in your thumb and index or middle fingers
  • Pain or numbness that worsens with:
    • Wrist, hand, or finger movement
    • Sleep (symptoms may wake you)
  • Hand stiffness or cramping that gets better after:
    • Shaking your hand
    • Waking up in the morning
  • Weakness or clumsiness of your hand:
    • Loss of grip strength
    • Difficulty making a fist
    • Frequently dropping things
  • Pain that moves up your arm

Diagnosis

The doctor will ask about your symptoms and medical history. A physical exam of your arms, wrists, and hands will be done. The exam will include tests of strength, sensation, and signs of nerve irritation or damage.

Other tests may include:

  • Electrodiagnostic exam—Measures and records the speed of electrical conduction in your median nerve (to see if the nerve impulse in the hand is delayed)
  • MRI scan—A test that uses magnetic waves to make pictures of structures inside your body, in this case the neck (cervical spine)
  • X-ray—A test that uses radiation to take a picture of structures inside your body, especially bones
  • Ultrasound—A test that uses sound waves to measure the width of your median nerve (may be used as a screening test or to guide injections)

Treatment

It is important to correct whatever is causing the carpal tunnel syndrome. Sometimes making simple changes in your workplace or home may help relieve symptoms.

Treatment may also include:

  • Rest your wrist by keeping it straight and decreasing activities that worsen pain.
  • Gently apply ice packs to the area.
  • Elevate the hand above your heart to reduce swelling.
  • Do exercises as directed by your healthcare provider.

A splint will prevent extreme movements of the wrist. It is most effective when worn at night. It can help you avoid waking up with symptoms.

  • Pain relievers, for example, aspirin and ibuprofen
  • Injection of cortisone into the carpal tunnel

Surgery may be needed if symptoms are severe, or continue after you try other treatments. The most common procedure is the carpal tunnel release.

If you are diagnosed with carpal tunnel syndrome, follow your doctor's instructions.

Prevention

You may reduce your chances of getting carpal tunnel syndrome by taking these steps: