It happens because of pressure on your median nerve, which runs the length of your arm, goes through a passage in your wrist called the carpal tunnel , and ends in your hand . The median controls the movement and feeling of your thumb and the movement of all your fingers except your pinky.

Carpal tunnel syndrome , also called median nerve compression, is a condition that causes numbness, tingling, or weakness in your hand.

Carpal Tunnel Syndrome 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.

Early on in the condition, shaking out your hands might help you feel better. But after some time, it may not make the numbness go away.

As carpal tunnel syndrome gets worse, you may have less grip strength because the muscles in your hand shrink. You’ll also have more pain and muscle cramping.

Your median nerve can’t work the way it should because of the irritation or pressure around it. This leads to: