Carpal Tunnel Syndrome

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

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Definition

Carpal tunnel syndrome is a nerve disorder of the hand 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.

Causes

Causes include:

• Repetitive movements of the hands, wrists, or fingers
• Use of vibrating equipment or tools
• A narrow carpal tunnel (due to heredity)
• Wrist injury:
  • Burns
  • Broken bones
  • Compression or crush injuries
• Arthritis
• Diabetes
• Raynaud's disease, which impairs blood flow in the hands
• Water retention from:
  • Heart failure
  • Kidney problems
• Hormone-related conditions
  • Pregnancy
  • Breastfeeding
  • Menopause
  • Hypothyroidism
  • Cushing's disease
  • Excess growth hormone
• Medications
  • Birth control pills
  • Cortisone pills or shots
  • Some high blood pressure drugs
• Tumors

Risk Factors

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

• Sex: Female
• Advancing age
• Obesity
• Lack of exercise
• Excessive alcohol consumption
• Smoking
• Jobs involving repeated hand motions
  • Assembly and processing plant workers
  • Computer operators
  • Typists
  • Beauticians
  • Cashiers
  • Construction workers
  • Cooks
  • Musicians
• Activities with repetitive hand motions
  • Certain sports
  • Sewing
  • Playing musical instruments

Symptoms

Carpal tunnel syndrome causes symptoms in one or both hands or wrists.

• Tingling, burning, or numbness, especially in the 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 the hand
  • Waking up in the morning
• Weakness or clumsiness of the hand
  • Loss of grip strength
  • Difficulty making a fist
  • Frequently dropping things
• Pain extending up the arm

Diagnosis

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

Other tests may include:

• Nerve conduction
• Electromyogram
• X-ray

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, ice, elevation and exercises

• Resting the wrist by keeping it straight and decreasing activities that worsen pain
• Gently applying ice packs to the area
• Elevating the hand above the heart to reduce swelling
• Exercises as directed by your health care provider

A wrist splint

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

Medications

• Pain relievers like aspirin or ibuprofen
• Injection of cortisone into the carpal tunnel

Surgery

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

Prevention

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

• Minimize repetitive hand movements when possible.
• Alternate between activities or tasks to reduce the strain on your body.
• When using your wrists, keep them straight and let your arms and shoulders share the stress.
• Use your whole hand or both hands to pick up an item.
• Avoid holding an object the same way for a long time.
• If you work in an office, adjust your desk, chair and keyboard so you are in the best possible position:
  • Back straight
  • Feet flat on the floor or resting on a footrest
  • Knees level with or slightly lower than your hips
  • Shoulders in a neutral position, not forward or back
  • Elbows bent at a 90 degree angle
  • Forearms parallel to the floor and wrists straight
• Take breaks at least once an hour to:
  • Rest or shake your hands
  • Massage the palms and backs of your hands
• Get regular aerobic exercise such as walking or swimming.
• Cut down on caffeine and smoking, which may reduce blood flow to your hands.

Organizations

American Academy of Orthopedic Surgeons
http://www.aaos.org

American Association of Neurological Surgeons
http://www.neurosurgery.org/aans

SOURCES:

"Understanding and managing carpal tunnel syndrome." Journal of Musculoskeletal Medicine, November 1999.

"Carpal Tunnel Syndrome." The Female Patient, August 1997, p.21-30.

"Carpal Tunnel Syndrome," Postgraduate Medicine, Sept 1995, p.216.

"Practical Management of Carpal Tunnel Syndrome." The Physician and Sportsmedicine, January 1995.

"Carpal Tunnel Sydrome: How you can help your patient overcome the symptoms." Consultant, February 1994.

"Carpal Tunnel Syndrome: A Practical Review." American Family Physician, May 1, 1994.

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Last reviewed June 2001 by Medical Review Board