About Itch

Human skin is composed of two layers: an outer layer called the epidermis and a deeper layer called the dermis. The region in between these two layers contains all the small nerves that send itch signals to your brain that contributes to your feeling of itch.

Itch, also called pruritus, is the unpleasant sensation that causes you to scratch. The underlying cause can be within the skin, the nerves, or other conditions affecting the rest of your body. For example, your kidneys, liver, and blood sugar levels may all contribute to itch. Itch and pain have similar pathways in the body; while pain causes you to withdraw from whatever is causing it, itch causes a desire to scratch.