With 20 square feet (2 square meters) of surface area covering the average human body, it's no surprise that skin can get itchy. And when hair, dust or other irritants make contact, there's a lot that has to happen before we respond with an almost reflexive scratch. Take our quiz to find out what goes on under the skin when it itches.
The average human body is covered by about 20 square feet (2 square meters) of skin.
The impulse to scratch a particular spot is known to scientists as "pruritus."
The spinal cord relays the information to your brain.
In a split second, receptors send a signal through fibers in the skin to the spinal cord and then to the brain.
Experts used to believe that itching was a form of light pain.
Scratching an itch is intended to remove an irritant as soon as possible.
When you scratch, the signal being sent to your brain that you have an itch is interrupted.
By scratching an irritant, you trigger more nerve endings than it covers.
There are numerous medical causes of itching, including allergies, infections and many diseases.
Skin is the only organ that is constantly under the threat of irritants.