Today’s Wonder of the Day was inspired by TYRELL. TYRELL Wonders, “WHAT IS AN ITCH? HOW COME WE FEEL IT?” Thanks for WONDERing with us, TYRELL!
You contort your body to try to reach the spot, but you can't seem to get your hands in the right place. The feeling intensifies and you feel compelled to rub your fingernails over that spot. You've got an itch and it needs to be scratched!
If you have a friend nearby, you might find yourself motioning to them to scratch the spot you just can't reach. If not, you'll probably end up wiggling in your chair as you try to rub your back against the chair. One thing is clear, though: one way or another, you're going to have to scratch that itch!
Itching, also known by the scientific term pruritus, can be a serious problem. After all, the skin is the body's largest organ. Most of us are covered by about 20 square feet of skin — and all that skin is constantly exposed to things that can irritate it.
All sorts of things can cause your skin to itch. Bug bites, dust, medical conditions, hair, allergies, clothing fibers, and skin problems are just a few of the many causes of itching. Although you might not like the sensation of your skin itching, it's actually one of your body's ways of protecting itself.
Like other defense mechanisms, itching is your skin's response to potential danger it senses from external stimuli. When those stimuli activate the pruriceptors of special nerve cells called C-fibers, the pruriceptors send itching signals to your brain via the spinal cord.
When your brain senses the itch, what does it tell your body to do? Scratch! The natural reaction to an itch is to scratch it with the fingernails. In many cases, the fingernails will dislodge or remove whatever external stimulus was causing the itching sensation, thereby alleviating the problem.
Sometimes, though, your fingernails won't necessarily get rid of the irritant. For example, if you get bitten by a mosquito, the chemical reaction taking place in the area of the skin with the bite will cause an ongoing itching sensation. Even though your fingernails don't get rid of the bite, scratching still feels good and temporarily relieves the itch. Why is that?
Scientists have learned that scratching the skin causes a small pain reaction. Typically, the area of skin affected by an itch is quite small. When we scratch the itch, we tend to scratch a much larger area of skin. The pain caused over a larger area of skin distracts from the itching sensation, providing temporary relief.
Recently, scientists have started to study the effect of serotonin on itching. Scientists know that scratching causes the brain to release serotonin, which is a hormone associated with pain relief. Scientists now believe serotonin may also make itching worse, which would finally help to explain why scratching only provides temporary relief and itching can seem worse after scratching.