Scratching an itch
25 Nov 2019, 11:46 am
When I look online about the biological explanation as to why scratching an itch feels good, none of the explanations I find make any sense. Let me go through the most common ones and tell you why I disagree.
1. One explanation is that pain signals block itch signals at the spinal cord. It doesn't make sense for two reasons:
a) When I scratch an itch, I want to scratch one very specific location. So if it was as far away as the spinal cord, it wouldn't make that much sense.
b) If it was as simple as "blocking" some signals, it won't feel so good. Think of anesthetic. Does it feel good when the dentist gives you local anesthetic? No. So why is scratching an itch any different if it was all there is to it.
2. The other explanation is that it is an instinct. I disagree with this as well. Its not like I scratch without thinking. I very much DO think about scratching and think "let me scratch this itch to make it go away, isn't it wonderful how nice it feels, I wonder what is the biology behind it". So if I think all those things while I scratch, clearly its not just an instinct.
3. The other thing I read is that creating physical pain disracts you from the itching. I have two problems with this as well:
a) If I was truly DISRACTED from itching, why would I be having the above described thoughts ABOUT it?
b) It it was just a need to be disracted why would I -- out of all the disractions around -- pick up scratching. Why aren't there any people who would INSTINCTIVELY read a book in response to itching. Sure, there MIGHT be some people who might FORCE THEMSELVES to read a book in order to stop themselves from scratching -- but thats not what I am talking about. What I am talking about is that the fact that it is natural to scratch but its not nearly as natural to read a book suggests that scratching is a lot more than just a disraction.
4. The other thing I read is that scratching makes itch worse. No it doesn't. It makes it better: which is precisely the reason why I scratch. Perhaps what they MEAN to say is that "it makes it better in the short run but then it makes it worse on the long run", but then they should actually say it this way. In any case, I didn't notice that scratching makes anything worse on the long run. All I know is that it makes it better.
5. They take that scratching helping an itch is a given and are focused on why it makes it worse. I actually want to do the opposite. If you scratch HEALTHY skin, it would make it hurt, wouldn't it. So why scratching makes something worse is a no-brainer. The REAL question is why does it make it better -- which it clearly DOES. So if -- despite the fact that scratching healthy skin would hurt -- in this particular case not only it doesn't hurt but it actually helps -- well, it means you must be doing SOMETHING right.
Personally, I have a few theories of why scratching makes you feel better:
A. When you have eczema, your skin gets red. Now, I am not a biologist, I am a physicist, but I really wish I knew the biology behind skin getting red. My THEORY is that maybe something happens to capilaries in the skin so that the blood gets stagnated. I am wondering how would those capilaries look under the microscope? Is it that they are broken so that the blood actually leaks out of those capilaries and thats why it can't flow any further, or could it be that they aren't broken but they change their shape somehow making it harder for the blood to flow? In any case, whatever is the case, the stagnated blood would collect all those toxins and stuff at that place where it stays -- particularly since that part of the skin is already unhealthy anyway (which is the other thing I wonder about: what if the doctor were to do a blood test at the spot affected by eczema instead of doing it at one of those standard locations -- would the blood results give anything different)? Anyway, the point I am trying to make is that scratching would help push that blood along and thus remove all those toxins that this part of the skin collects
B. While scratching itself doesn't block the itch sensation (itch sensation has to play SOME role in order for scratching to be so pleasurable) it combines with it to produce a sensation of a third kind. Think of colors. If you combine yellow and blue, you get green. Now, green is neither yellow nor blue, its some third color. So think of itch as yellow and pain as blue, and think of the sensation of scratching an itch as green. Now, its quite amaizing that we all, collectively, hate both yellow and blue yet love green. Maybe if someone had different taste the whole scratching itching relation for that person would have been different. But it is what it is.
C. This one I actually read somewhere but I didn't save the link and I don't know where it is (I read it few years ago). When you scratch a skin, you produce some damage -- however small it might be -- so your body sends T-cells to cure the damage produced by scratching -- and those T cells happened to cure the eczema damage as well. Here is an analogy. Lets say you have a really bad eczema and you want to see a doctor. But the doctor says "nope, I can't take patients for eczema, because I have patients with more serious issues". Yet you know that -- as weird as it sounds -- that doctor DOES treat simple cuts, he just doesn't treat eczema. So what do you do? You purposely cut yourself -- so then the doctor WILL agree to see you -- and then during that appointment he will treat eczema too. That is the sort of thing that might be happening between the body and T cells.
D. If we go back to that stuff about "pain sensation produced by scratching blocking an itch" -- how about we do it the other way around and say "when you HAVE to scratch in order to remove the dirt from the wound -- yet its too painful to do so -- you need an ITCH to block the PAIN so that you CAN do what you HAVE to do". That actually happened to me when it comes to anal itch. My anal itch is clearly caused by the fact that I don't wipe my anus carefully enough (which by the way brings a host of other misconceptions -- people are going back and forth between saying its a mystery why anus itches and saying that its because they clean it too much -- nope, its because they don't clean it enough, which should be obvious -- I mean think about it, anus is the only part of your body that has all this fecal matter on it, and its the part of the body that itches, how much more obvious does it have to be?) In any case, sometimes I can't wipe my anus for the simple reason that its too painful to do so because of all that damaged skin. But then, few hours later, it begins to itch. And once it itches I use the toilet paper to scratch it, AND thats when I get it totally cleaned up. So you see, itching is a good thing, isn't it. And it wasn't about pain blocking an itch, it was about itch blocking a pain: itch allowed me to wipe my anus without the pain I would have otherwise felt! Now, isn't it a good thing?
30 Nov 2019, 1:53 pm
Your objections don't make sense to me.
Most itching is caused by dead skin. And scractching is your body's way to remove the dead skin.
The spinal column runs your nervous system. Does the scutwork so your brain doesn't have to do it. Like reflexes. When the doctor hits your knee with that rubber hammer and your leg involuntarily kicks up - its because your knee sent a signal to your spinal column, and your spinal column ordered your knee to kick.
If your nose itches, I dunno if its your brain or your spinal column, but the signal gets convey that you need to scratch the specific spot that's crying out to be scratched. So you get the urge to scratch that particular spot. The fact that you think about it for a second before deciding to actually scratch- and can resist the urge if the itching spot is from an insect bite- and momma told you not to scratch bug bites "because it will only make it worse" doesn't change the instinctive nature of it.
