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

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:
Slower nerve impulses
Less feeling in your fingers
Less strength and coordination, especially the ability to use your thumb to pinch