Carpal tunnel syndrome

Definition

Carpal tunnel syndrome is compression of the median nerve at the wrist, which may result in numbness, tingling, weakness, or muscle damage in the hand and fingers.

Alternative Names

Median nerve dysfunction

Causes, incidence, and risk factors

Carpal tunnel syndrome is caused by pressure on the median nerve at the point where it passes through the wrist. The median nerve supplies sensation to the thumb side of the palm, and to the thumb, index finger, middle finger, and the thumb side of the ring finger. It also helps with movement to part of the hand.

The area where the nerve enters the hand is called the carpal tunnel. Since the passageway is stiff, any swelling in this area can put pressure on the nerve. This may also be called entrapment of the nerve.

Injury to the wrist area can cause swelling of the tissues and carpal tunnel syndrome. This type of injury may be caused by sports such as racquetball and handball, or occur during sewing, typing, driving, assembly-line work, painting, writing, use of tools (especially hand tools or tools that vibrate), or similar activities.

Carpal tunnel syndrome is common in people who perform repetitive motions of the hand and wrist, such as typing. The condition occurs most often in people 30 to 60 years old, and is more common in women than men.

Some of the conditions associated with carpal tunnel syndrome include:

• Acromegaly
• Diabetes
• High blood pressure
• Hypothyroidism
• Kidney failure
• Menopause
• Multiple myeloma
• Obesity
• Pregnancy
• Premenstrual syndrome (PMS)
• Recent fungal infection
• Recent tuberculosis
• Rheumatoid arthritis

Symptoms

• Numbness or tingling in the thumb and next two or three fingers of one or both hands
• Numbness or tingling of the palm of the hand
• Pain extending to the elbow
• Pain in wrist or hand in one or both hands
• Problems with fine finger movements (coordination) in one or both hands
• Wasting 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