What Is Carpal Tunnel Syndrome?
The carpal tunnel is a narrow passageway on the palm side of your wrist made up of bones and ligaments. The median nerve, which controls sensation and movement in the thumb and first three fingers, runs through this passageway along with tendons to the fingers and thumb. When it's pinched or compressed, the result is numbness, tingling, weakness, or pain in the hand, called carpal tunnel syndrome.
Symptoms: Pain and Tingling
Carpal tunnel develops slowly. At first, you're most likely to notice it at night or when you first wake up in the morning. The feeling is similar to the "pins-and-needles" sensation you get when your hand falls asleep. During the day, you may notice pain or tingling when holding things, like a phone or a book, or when driving. Shaking or moving your fingers usually helps.
Symptoms: Weakness
As carpal tunnel syndrome progresses, you may begin to notice weakness in your thumb and first two fingers, and it may be difficult to make a fist or grasp objects. You may find yourself dropping things, or you may have trouble doing things like holding a utensil or buttoning your shirt.
Symptoms: Sensation Problems
Carpal tunnel syndrome can also cause a feeling of numbness in the hands. Some people feel like their fingers are swollen, even though no swelling is present, or they may have trouble distinguishing between hot and cold.
What Causes Carpal Tunnel Syndrome?
There usually isn't one definitive cause of carpal tunnel syndrome. Because the carpal tunnel is narrow and rigid, anytime there is swelling or inflammation in the area, the median nerve can be compressed and cause pain. Symptoms may be present in one or both hands (usually symptoms develop in the dominant hand first).
Who Gets Carpal Tunnel Syndrome?
Women are three times more likely than men to get carpal tunnel syndrome. Certain conditions can also increase your risk. These include:
• Diabetes, gout, hypothyroidism, and rheumatoid arthritis
• Pregnancy
• Sprain or fracture of the wrist
• Could Your Job Be to Blame?
• It's a common belief that frequent typing can lead to carpal tunnel syndrome. But it's actually three times more common among assembly line workers than it is among data-entry personnel -- and frequent use of vibrating hand tools increases the risk. In contrast, a 2001 study found that even heavy computer use -- up to seven hours a day -- did not make people more likely to develop carpal tunnel syndrome.
What Happens Without Treatment?
• At first, symptoms of carpal tunnel syndrome come and go, but as the condition worsens, symptoms may become constant. Pain may radiate up the arm all the way to the shoulder. Over time, if untreated, carpal tunnel syndrome can cause the muscles on the thumb side of your hand to waste away (atrophy). Even with treatment, strength and sensation may never be completely restored
Carpal Tunnel or Something Else?
A few conditions have symptoms that can mimic carpal tunnel syndrome. These include:
• Injury to a muscle, ligament, or tendon
• Arthritis of the thumb or wrist
• Nerve problems such as diabetic neuropathy
Your doctor will do tests to rule out other health conditions.
Diagnosing Carpal Tunnel Syndrome
There are several tests your doctor will perform to see if you have carpal tunnel syndrome. The Tinel test involves tapping on the median nerve to see if it causes tingling in the fingers. In the Phalen test, the doctor will have you press the backs of your hands together for a minute to see if this causes numbness or tingling.
Electrodiagnostic Tests
To confirm the diagnosis, your doctor will order a nerve conduction study. In this test, electrodes are placed on the hands and wrists, and small electric shocks are applied to measure how quickly the median nerve transmits impulses. Another test, called electromyography, uses a fine needle inserted into a muscle to measure electrical activity and assess damage to the median nerve.
Treatment: Rest and Immobilization
Underlying causes such as diabetes or arthritis will need treatment. Then your doctor may advise resting the hand and wrist and wearing a brace to limit movement. Night use is important to prevent the wrist from curling during sleep, which can make your symptoms flare up. Non-steroidal anti-inflammatory drugs such as ibuprofen and naproxen, along with cold compresses, can reduce pain.
Medications for Carpal Tunnel
When carpal tunnel symptoms are more severe, your doctor may recommend corticosteroids by injection or by mouth. Steroids can temporarily reduce inflammation around the median nerve and ease your symptoms. Injection of a local anesthetic such as lidocaine can also relieve symptoms. Other things that may help include diuretics, also known as “water pills,” which reduce swelling, and vitamin B6 supplements
