What Is Carpal Tunnel Syndrome?

Carpal tunnel syndrome, also called median nerve compression, is a condition that causes numbness, tingling, or weakness on the side of your hand near the thumb. The median nerve is located on the palm side of your hand aka the carpal tunnel. The median nerve provides sensation to your thumb, index finger, long finger, and part of the ring finger. It supplies the impulse to the muscle going to the thumb. Carpal tunnel syndrome can occur in one or both of your hands.

Causes

The pain in your carpal tunnel is due to excess pressure in your wrist and on the median nerve. Inflammation can cause swelling. The most common cause of this inflammation is an underlying medical condition that causes swelling in the wrist, and sometimes obstructed blood flow. Some of the most frequent conditions linked with carpal tunnel syndrome are:

• diabetes
• thyroid dysfunction
• fluid retention from pregnancy or menopause
• high blood pressure
• autoimmune disorders such as rheumatoid arthritis
• fractures or trauma to the wrist

Carpal tunnel syndrome can be made worse if the wrist is overextended repeatedly. Repeated motion of your wrist contributes to swelling and compression of the median nerve. This may be the result of:

• positioning of your wrists while using your keyboard or mouse
• prolonged exposure to vibrations from using hand tools or power tools
• any repeated movement that overextends your wrist, such as playing the piano or typing

Signs & Symptoms

Symptoms of carpal tunnel include:

• Burning, tingling, or itching numbness in your palm and thumb or your index and middle fingers
• Weakness in your hand and trouble holding things
• Shock-like feelings that move into your fingers
• Tingling that moves up into your arm

You might first notice that your fingers “fall asleep” and become numb at night. It usually happens because of how you hold your hand while you sleep.

In the morning, you may wake up with numbness and tingling in your hands that may run all the way to your shoulder. During the day, your symptoms might flare up while you’re holding something with your wrist bent, like when you’re driving or reading a book.

• Phalen’s Maneuver – Firmly hold the backs of your hands together with your fingers pointing down, while keeping your arms parallel to the floor. If within a minute, you experience numbness, tingling, pain or a combination, you likely have nerve involvement.

• Tinel’s Sign – Use your finger to repeatedly tap the volar carpal ligament, the ligament just under the skin in the centre of your wrist. If the tapping elicits numbness, tingling or pain, then you may well have carpal tunnel syndrome.