That’s what I typed into google this morning.
Itching, or “pruritus”, is caused by an interaction between our skin cells and nervous system. Some of your nerves (called pruriceptors) are itch-sensing. When they’re stimulated, your brain releases something called histamines, triggering the itch. And the reason scratching feels so good is because it overrides the itching sensation by sending pain signals to the brain, and in response the brain sends out certain chemicals to provide relief. Unfortunately, some of these chemicals can reactivate the itch. This explains the itch-scratch cycle. Dang.
But what causes these itch-sensing nerves to be stimulated? Well, a lot of things. There used to be an advantage to the thing we call an itch, as it let you know if something was wrong. But, after millions of years, its effectiveness and necessity have slowly worn out.
Certain medications can lead to itchiness, as can illnesses. There are also itches that are completely in your head, but those are quite rare. Things like anxiety and stress can also be the cause of irritation. And of course, the most common reason, dry skin.
What about… I don’t want to say it, but… phantom itches? Ugh! The ones you just can’t seem to find, no matter how hard you try. Nightmare fuel, they are. The reason they exist is because you have more nerves in some parts of your body than others, and in the places with fewer nerves, there is less accuracy. That then leads you to think you have an itch in a place you really don’t. Blegh.
To sum this up, I’m most definitely not a scientist, and I’m not one hundred percent sure of the things I’ve written. I was just curious! All of my citations are below if you want to check things out for yourself.
Citations:
Lindberg, Sara. “Why Do We Itch? Why Does Scratching Feel Better?” Healthline, Healthline Media, 27 Feb. 2020, www.healthline.com/health/why-do-we-itch.
Shortsleeve, Cassie. “Why Do We Itch? The Scientific Causes Are Actually Rooted in Evolution.” Prevention, 18 Oct. 2019, www.prevention.com/health/a29388354/what-causes-itching/.
MacDonald, Fiona. “Here’s Why You Get Itchy, And Why Scratching Feels So Good.” ScienceAlert, www.sciencealert.com/some-disorders-make-you-itch-uncontrollably-so-much-so-that-one-woman-scratched-through-to-her-brain.
