Nails are acellular, non-living material. They are mainly made of the protein keratin, which is laid down by the nail matrix, which is under, and slightly closer to the wrist from, the cuticle.
The rate of growth of finger nails varies tremendously from person to person, and even from finger to finger (thumbs are the fastest), but does NOT vary from side to side to side of a given nail.
Cites for this are difficult to come by, since this falls in between what is available in the on-line Comptom’s & what is published in medical journals. Here is a decent basic info site: http://nh.ultranet.com/~mhabif/html/anatomy.html
Nails grow at a pretty steady rate, gradually slowing down as we get older. Even though healthy nails constantly grow, they lengthen at a slower rate, because the tips of them are being worn down at a rate slower then the rate of growth.
Rate of growth = a mm/month
Rate of wear = b mm/month
a > b
Rate of lengthening = a-b mm/month
Note: b varies with nail thickness/hardness, nail length, and the harshness of hand activities.
Think of a nail file or emory board, Ray. It is pretty easy to shorten nails by a measureable amount in a few minutes with one of these. Albeit more slowly, the same thing happens when our fingertips run across any rough surface.
When part of a nail is lost, the part that remains at normal length projects further from the nail bed than the damaged section, thus it is more exposed to normal wear, while the damaged portion of the nail is protected.
Rate of lengthening for damaged nail = a (since it is protected from wear)
Rate of lengthening for undamaged nail = a-b
Since a > a-b, the damaged nail appears to be catching up to the undamaged section.
Rate of growth for the entire nail = a.
You certainly can try the fingernail polish experiment if you choose. Or you can accept what quite a few people have told you. I can tell you that fingernails sometimes get horizontal ridges, or white bands, indicating keratin that came out differently during a period of illness, nutritional lack, or trauma to the nail matrix. I have looked at a lot of fingernails, Ray. These lines have always remained perfectly straight, with no distortion whatsoever, in every case.
btw, “take it to the pit” means that the discussants start a new thread in the Pit to continue their rants, rather than clutter other forums with closed-minded, prejudiced diatribe.
Sue from El Paso
Experience is what you get when you didn’t get what you wanted.
No, I take exception to your constant haranguing of physicians and your implications that they know nothing about the human body. Jesus, we learned how fingernails grow in my freshman biology class, so forgive me if I believe that physicians, who take much more biology than I, and probably you, ever did, might conceiveably know more about it (biology and the way the human body, including fingernails, works) than I do.
Please quote where I said one word about money or pay.
If you think all that doctors do in college and medical school is memorization…I’m not going to finish that sentence, because it’s get nasty.
My work switches me from the office to the work site on a regular basis. I’ll be in the office for anywhere from a week to several weeks, then spend a day or two at a scalehouse, or working in an industrial process control setting, or pulling wire & cable through some wall or crawl space.
I keep my nails fairly short out of habit (hey, I’m a guy), but when I move from the office (where they are relatively protected from major damage) to the work site, I’m pretty much guaranteed to break one or two if they extend at all past my finger tip. So I’m frequently in the situation of having a nail that’s been broken off, sometimes very unevenly.
My nails, at least, do not seem to grow at an uneven rate from side to side. I have to trim the undamaged side several times, often over over a couple of weeks, before ever having to trim the damaged side.
The assorted lines on my nails caused by smacking them various tools always seem to stay at the same relative angle, again sometimes for weeks, while the damage grows out.
So for me, anyway, the situation is exactly as described by MajorMD and the others who disagree with the OP.
I must have smashed the crap out of one of my fingers without knowing it, or slept on it wrong, or something. I woke up once in the middle of the night with the tip of my middle finger on my left hand about twice the size of the other fingertip. I took some Aleve, soaked it in peroxide, and forgot about it.
Two weeks later, I notice a yellow spot growing out on one side of that fingernail. It got bigger and bigger, and after it grew out for a while, started cracking. I now have a large hole in the base of my nail, and there’s no sign of new nail growing up to replace it.
I have a real life experience to add to this thread, though it doesn’t seem to be what is driving it. I can’t even make enough sense of all the bickering to know which side of the arguement this may fall.
I have two fingers with flaws in the nail for a long time (long time). The nail on my right thumb is split back beyond the cuticle, the two parts grow completely independent of each other. The right side is about 1/8 inch wide and it seems to grow slightly faster than the main portion of the nail. As, when the nail needs cutting, the smaller portion is slightly longer than the nail right next to it that is part of the main nail.
Now to the second finger of my right hand. (ok, I’m left handed, my right hand is the sacrificial lamb). It has a damaged portion just on the right side of the center about 1/16 inch wide. The two portions of the nail are not separated but the damaged area is very thin. If the nail grows out even slightly it will split into the thin part and has to be cut back way too far to get beyond the split. Both sides seem to grow at the same rate.
Now, my deductions. In the case of the thumb, the 2 portions are growing independently but at close to the same rate, although not exactly. In the case of the middle finger, the entire nails grows at a certain rate and if a damaged area can’t supply the needed material then it is just thinner and weaker.
Now, exactly whose side this ends up supporting, I don’t have a clue, but I would like one answer and that is, how anyone can take something like the way a finger nail grows to the level of attacking another personally or should that be another thread entirely.
Uh… If you could have “smashed the crap out of…one of (your) fingers” without remembering it, I’m left to wonder what or who else was smashed.
Seriously, this is not something I can diagnose over the 'net; 2 likely causes are infections or foreign body under the cuticle.
If I’m hearing you right & the “hole” is growing into a linear gap, do go see a doc - one who can/will do scrapings & look at them under a microscope, or who will send to someone who will. If you can self-refer to a dermatologist, do that.
Good luck!
Sue from El Paso
Experience is what you get when you didn’t get what you wanted.
While Nanobyte often participates in a jocular, informative manner in most subjects, he has been known to go on knee-jerk anti-MD rants as a matter of principle. It’s obvious that, to him, the medical community is a big sham. So, take his critiques of medical knowledge in that light and ignore him.
::Note to self - Never hold a nail if Jim is hammering::
Jim, I’m sorry you had to read through the nastiness. Looks like you’re a fairly new poster. I don’t know how long you’ve been lurking, but when you see that much venom with no obvious source, there’s a history somewhere. Sometimes it’s on-line, where bad feelings have been caused by other posts in other threads; sometimes it’s just the emotional baggage we all carry. Nanobyte has posted on several threads his feelings towards docs; I don’t know the history behind that, but I’m sure there is one. Other readers, apparently, are tired of having to pick their way through the minefield.
Your finger agrees with everything I said. The fact that your thumb nail segments have different growth rates allows me to elaborate on my basic answer (which assumed that the nail was intact). Nails that have completely or partially lost contact with the nail bed underneath them do grow faster. I suspect that the small part of your nail is less strongly attached to the nail bed.
By the way, if this piece causes problems, it can be removed & if the nail bed is destryedm that small section will not grow back - same treatment as for ingrown hangnails.
Sue from El Paso
Experience is what you get when you didn’t get what you wanted.
Sue, thanks for the info. Been reading the message boards for a little while, straightdope for a long time. I don’t normally post though. (lurkng is such a harsh term).
Good idea, that’s exactly how it happened. But it’s been that way for 30 years(did I say that?), so it isn’t a big deal. The middle finger flaw is much more bothersome and it came from and infection.
Oh, and Sue, also you are probably right about not being in less strongly (I like that phrase, kinda like more weakly, only different) attached to the nail bed. As the small portion of the nail grows out, it seems to get more loosely, or is it less tightly, attached to the nail bed to the point that it seems it could pull completely loose if it isn’t trimmed back.
I agree. I assume the amount of distortion of the line would be greater for a more distal line.
AuMatar:
Up until the last word of this, ‘off’, it describes what I’ve observed and stated in my OP; i.e., the damaged side grows a little faster and tends to catch up with the undamaged side, making the two sides more even, and usually nearly even, before the undamaged side needs to be trimmed. If your word ‘off’ means (with ‘nail curve’ = ‘distal edge of nail’) the distal edge of the nail is more extended on the damaged side, what you say seems to present a case where the damaged side would actually overtake the undamaged side. I certainly didn’t claim that would happen.
I have, of course, not counted molecules (probably these are long chains that get broken from abrasion anyhow, so I wouldn’t want to use that sort of measure), what I was trying to say was that the rate of abrasion is negligible wrt rate of growth of either portion of the nail.
647:
Hey, we’re talking here about a damaged part of a nail catching up with the nail’s other part. . .not Flatlanders catching up with modern astronomy.
I didn’t say I knew, right? I just observed what happens and then asked this ‘how’ question in general, however* whatever materials might get into the act. The Web page Sue linked to here suggests, though, how this might occur. See my discussion in this post directed to Sue, below.
Where did I say I didn’t feel it wouldn’t? My OP question, of course, as a result of my observations, went on from the position of acceptance of the catch-up phenomenon to ask what the mechanism for it might be. From you others’ standpoint of not accepting this premise of mine, of course, the mere existence or nonexistence of the phenomenon needs to be established, and of course, the best Straight Dope way is a real-life experiment that first off demonstrates that the phenomenon either exists or not.
Nickrz:
I just don’t think this place should turn into a doctors’ or lawyers’ public-counseling session. I think MDs and JDs/LLDs should be required to play here by the same commonsense and scientific rules that others are susceptible to on objective, real-world questions here in this MB.
Well, we don’t have forever. I think a webcam focused on someone with fast-growing finger- or toenails should be set up at this site. You should get the SD staff to do this. Rotsaruck. You don’t think they’d think it was as important as the duck-echo experiment? (And you know it wouldn’t make the WSJ, like the HUD fiasco.) A sped-up time-lapse video clip of a semi-damaged nail would be good, only if there were some way to establish it’s authenticity. Maybe the webcam thing could be used for increased SD publicity, ya think? Not enough sex? Nobody but foot fetishists would be attracted?
Sue:
Well, yes, that has been your claim and that of some others here. I do not disagree with that, of course, in the case of a normal, undamaged, undiseased and not-irregularly-broken-at-its-distal-end nail with normal supporting and productive tissues. I doubt that you are claiming no sidewise growth variation in the case of nails with their productive tissues damaged or diseased. I’m not sure what you would say about nails with healthy, fully functioning productive tissues but which have “disease” in them per se. Would you recognize that a fungus chomping on the keratin only could vary the net rate of extension of the nail’s distal edge, from side to side, in the same manner the significant differential abrasian you claim, in the case of a partially broken nail-end, would do?But I understand that our contest to be probably only over the such sidewise net-extension/growth variation in the case where nothing is nonuniform from side to side, except the amount of breakage at the distal end of the nail. Furthermore, I am claiming the existence of this growth variation, whether or not the breakage extends back to a part of the nail that is not bonded to the bed.
Truth is difficult to come by.
Yes, of course, but I say b << a, i.e., negligible within, say, a normal office worker’s lifestyle while not engaging in any obviously nail-eroding activities. I am impressed that, as an MD (a generally math-hating profession), you at least go so far as to outline a physiological issue in algebra. However, if the relative magnitudes of the parameters so designated are not established for the given problem space, you cannot claim anything more useful than what one finds in the many books of nebulous would-be theoreticians who go so far as to form sentences in math notation, while contributing nothing to make one believe they are presenting anything more than they would’ve, had they phased the same thing in a verbal language.
Well, I have actually gone further and used one on my nails, and I’m impressed at how much more shearing action is involved with such a tool – where it is a normal, full-sized, quality one or the other – than is involved in any other material contact that goes on with my fingernail tips. You know, I never did get into the habit of getting a rise out of my teachers and classmates by scraping my fingernails on chalkboards (in the good old days). I also note how totally ineffective, in the filing of my nails, are miniature key-ring-clipper nail files. A nail of mine could outgrow what I could file with one of them, no sweat.
Since b << a, and here, even more << than above (here, a difference in wearing), definitely no significant catch
Just a note to say that Majormd (Sue) is away at a medical conference and will not see this post until Thursday at the earliest. I don’t know if she will choose to reply, but I didn’t want the intervening silence to be taken in the wrong way.
And Ray, you make some claims about MD’s and their education. While these may not be directed at Sue directl, I think that you should know a couple of things about Sue that she would never tell you herself. She has a BS in Microbiology (Phi Beta Kappa) and an MS in Biochemistry. She received these degrees in 9 semesters. She then worked in a hospital lab for four years before attending Medical School. She was in the top 10% of her graduating class, and an Alpha Omega Alpha (med school equivalent of Phi Beta Kappa) graduate. Oh yeah, I forgot to mention, she was required to take Calculus 1 for her degree program, she took and made A’s in Calculus 2 and 3 because she enjoys math.
Uh-oh, now that you spilled the beans. . . Well, yeah, she’s obviously more than a cut above the rest intellectually, and I guess in some other ways. My main concern here is really how the others act, once an MD or attorney comments on something here. Categorically, those in both fields are extremely underwhelming and overbearing.
I have a (nasty) habit of cutting my cuticles back with an exacto knife (please, no lectures while I’m humbling myself to this cause). I sometimes get a bit beyond just cutting the cutlicle, to the point where I’ll actually ‘score’ the nail with a perfect outline of the cuticle.
In an embarassing exhibition of my roofing ability three week ago, I damaged a nail I had scored as above. I fortunately still have the reflexes of a (big) cat, and was able to get away with striking only the very tip of my left index finger nail, cracking off a jagged piece on the thumb side for about 1/3 of the nail width, to a depth of about 1/3 of the way to the cuticle (from where it attached under the tip of the nail.
As I sit here now, the scored line is about 3/4 of the way up the nail, and appears as it was when originally scored. The damaged area has just been trimmed away to ‘even’ today.
My observation is that MY nail grew at a common rate across the nail. I’m not sure how a nail could grow at different rates. I thought the nail itself was , basically, ‘dead’. How would one part grow past the other? Well, in my experience with this one nail, it grew the same across the damaged and undamaged part.
Chuck L.
“The intellectuals’ chief cause of anguish are one another’s works.”
Jacques Barzun
Cheers! CAL
You know, when I put either ‘moriah’ or ‘mariah’ into AltaVista search engine, I get an awful lot of associations of both of them with the wind. How do you get the real Wind to stand up and blow the other one out?
Apologies in advance to anyone who’s reading this while eating. A couple of months ago, my left thumbnail was ripped out in a bizarre puppetry accident. The normally hidden bottom part of the nail was pushed through the skin that covered it, resulting in the loss of the nail, a large gash at the base, a hydrant’s worth of blood and lots of ugly damage to the skin under the nail. It was reconstructed and after a while, I began to realize that what I thought was thickened skin over the area was actually the nail reforming (as of tonight, it’s obviously a complete nail again). The odd thing is, the part of the nail to the right of where the gash had been is growing a lot slower than the part on the left (there’s almost a quarter-inch of difference). I hope this helps to illuminate something about the topic, because if not, all I’ve succeeded in doing is making everyone ill.
I LOVE this idea. Not only would this resolve this question which has plagued mankind (with the exception of the medical community) for so long, but it would be entertainment for those people who find watching paint dry way too exciting.
ROTFLMAO
I love you guys.
