What Causes Carpal Tunnel Syndrome?
Carpal tunnel syndrome is a localized peripheral neuropathy that affects the hands.
At the base of the hand is a narrow place between bones and ligament where the median nerve and tendons are found. This area is called the carpal tunnel. When the median nerve, which runs from the forearm into the hand, becomes pressed, squeezed or inflamed at the wrist, the result may be numbness, pain and weakness in the hand and wrist, frequently reaching up along the arm.
Symptoms of carpal tunnel syndrome (CTS) may increase gradually. Signs of CTS usually are first noticed at night. Common symptoms include burning, tingling or numbness in the palm of the hand and along the fingers, especially the thumb, index and middle finger. These feelings may intensify to the point where it becomes difficult to hold small objects or to make a fist. The pain associated with this condition can range from mild-to-severe.
Carpal tunnel syndrome is typically the result of increased pressure on the median nerve and tendons in the carpal tunnel, rather than problem with the nerve itself. This pressure may be a result of arthritis, thyroid disease, trauma or injury to the wrist. CTS usually occurs in adults between 40 and 60 years of age, and is more common in women than men. In women, CTS may be caused by fluid retention due to pregnancy or menopause. Sometimes the exact cause of CTS cannot be identified.
CTS sometimes may be caused by work-related, repetitive activities that involve forceful or awkward movements of the wrist or fingers. However, a Mayo Clinic study (published in the June 2001 journal of Neurology), found that significant computer use (defined as an average of six hours per day) does not increase the risk of developing CTS.
If identified and treated as early as possible—with underlying causes such as diabetes or arthritis treated first—most people with CTS can relieve the pain and numbness and restore normal use of their wrists and hands.
Symptoms & Signs
(Not all carpal tunnel syndrome symptoms and signs may be present.)
In hand and fingers:
- Loss of movement
- Mild-to-severe pain (may experience pain at night)
- Decreased sensation
- Decreased strength
Other symptoms may include:
- Tendency to drop things
- Difficulty manipulating small objects
Evaluation & Tests
(Not all evaluation and tests may be necessary.)
- Physical examination
- Neurological evaluation
- Nerve conduction velocity test
Treatment & Therapy
(Not all treatments and therapies may be indicated.)
Treatment focuses on identifying and removing or correcting the underlying cause of the nerve dysfunction.
Treatment options include:
- Vocational or occupational counseling
- Wrist splint
- Over-the-counter pain medications (For severe pain, take over-the-counter pain medications and/or prescription drugs used for peripheral neuropathy, on a regular basis—rather than waiting until nighttime when symptoms can become more severe.)
- Carpal Tunnel Syndrome surgery
- Physical therapy to improve strength in the hand
- Take safety measures to compensate for loss of sensation