(no subject)

[xiphias]

I wonder if anyone, in any culture, ever worked out "diagnosis by smell."

I mean, certain dogs appear to be able to smell certain cancers. And it seems reasonable to assume that diseases cause biochemical changes in a person, and that those changes would lead to their body odors changing.

In its most blatant form, I think "the smell of sickness", in high enough concentrations, is one of those smells, like, "decomposition", which seems hard-coded into our brains. It's just one of those smells that you know what it is when you smell it.

But in much smaller terms, you've probably noticed how the people you're close to change smells when they're sick -- and I'm not just talking about "not showering/not brushing teeth" stuff -- someone who's sick who doesn't do that will smell different than the same person simply being a disgusting slob but otherwise healthy.

And, of course, at a certain stage of pregnancy, you can smell it. Or at least, my father can.

But I wonder if it could be taken further than that.

As I was just now getting ready for bed, and washing my face and arms, I noticed that the sweat on my forearms smelled different than it usually does. I could detect my normal scent, but I also detected a sort of charcoal-y, ashy overtone. Along with a sort of "grass" note.

And I wonder if this sort of thing could be used as a diagnostic aid, or if it ever HAS been in any culture. I mean, if you had a tribal healer who had a good sense of smell, who knew the people in the tribe very well, and who had a lifetime of experience doing this, I can imagine him or her picking some of this by experience.

But how would you pass the knowledge on to another generation? I mean, for common things, sure. "Okay, this is what a basic fever smells like." But that's not really THAT useful.

I mean, I guess it could be useful in a "Hey, Johnny -- you're probably gonna come down with something in a couple days -- why don't you go sleep in the sick tent on the outside of camp so you don't pass it along to the rest of us, and why don't you skip out on this hunting trip where we'll be gone for most of a week" way.

Anyway, this has been another in my ongoing series on "Olfactory Prowess: What Can Smell Do For You?" Brought to you by the Council On Getting People To Respect Our Most Under-Utilized Sense.

Comments

[tylik.livejournal.com]

A lot of diseases have pretty distinctive smells, but apparently this sort of thing is mostly no longer taught in med schools, so unless you're lucky enough to work with an oldtimer you don't learn it so much.

[the-siobhan.livejournal.com]

Gonorrhea for example. Hooo nelly!

I've read that gangrene is pretty distinctive too.

[xiphias.livejournal.com]

Yeah, but. . . I rather suspect that gangrene is one of those smells that is hardwired. From what I understand, you know it when you smell it, even if you've never smelled it before.

[gilmoure.livejournal.com]

Decaying flesh is decaying flesh. Ever smelled a dirty garbage can behind a restaurant? Just ignore the decaying plant smells.

There was an article (on slashdot or new scientist) a couple weeks ago, about a study where it turns out, people can learn how to follow a scent track across a meadow just like a dog. Apparently, our sense of smell is somewhat acute but most of us don't pay attention to it.

[xiphias.livejournal.com]

Yeah, apparently the reason our nose is apparently less acute is simply because it's farther away from everything.

Now, bloodhounds and other scent houds do, genuinely, have amazingly better senses of smell than we do, but then, they have amazingly better senses of smell than other dogs do, too.

I'm pretty sure my sense of smell is at least as good as my cat's. Cats aren't known for amazing senses of smell, anyway. She can HEAR the tuna can being opened, but she can't usually SMELL the tuna, unless I walk into the room with it. And I can smell a tuna sandwich from about the same distance as she can.

[gilmoure.livejournal.com]

From this study, they determined that our sense of smell is stereo and people were able to differentiate the direction of the scent track (which wasn't straight), by which nostril got a whiff first. People ended up doing the head swinging back and forth across the track. Also, people generally took a closer path to the track than dogs, with ranged about three times the distance across the track. Now, this could be due to dogs just liking to run around like mad men (at least from my experience with dogs, since getting married to an asthmatic allergic to cats). I think the scent they used was a combination of coffee and chocolate. Hmmm...chocolate...aargle...drool...

Here's the start of the article. Coulda' swore I read the entire thing. Someone on slashdot may have posted a link to the whole thing.

[pocketnaomi.livejournal.com]

Scent has been used pretty frequently in determining whether infection is truly gone or not in a wound. And sweet taste in the urine was the standard diagnostic for diabetes in ancient times.

[tiger-spot.livejournal.com]

I've used smell to tell if there's something wrong with my pet rats, but that's usually just "Whoa, nasty breath -- did that tooth abscess again?" or "Let's see if this wound I've been squirting antiseptic stuff at for a week is really clean or whether there's some nasty left under that scab"; infection of surface wounds rather than more subtle problems. I haven't been able to smell when they've had tumors, for instance.

[quietann.livejournal.com]

oh, and rat abcesses smell *nasty* :)

[kightp.livejournal.com]

I've read about "primitive" cultures where the healers/shamans sniff the sick person to determine what was wrong with them. And ... hmmm ... somewhere in the recesses of my mind is a bit of trivia about medieval physicians doing the same thing. I just can't retrieve it from storage at the moment. (-:

[adrian-turtle.livejournal.com]

It's the kind of thing that used to be taught to medical trainees. It isn't done much these days, partly because there are so many measurement techniques that are respected more than sensible ones -- the modern measurements are clean and "scientific," they're quantifiable.

It doesn't make much sense to describe the smell of an abcessed tooth in a textbook. I don't think I could come closer than "rotting meat." The medical trainee has to stand right there next to an experienced doctor who can point out an abcess in a patient they are both looking at, and talk about how it's different from the gangrenous rotting meat smell or the gout treatment rotting meat smell. (I once kissed someone at the start of a con and asked him how long he'd been taking antibiotics for his toothache. He told me. I said, "It's not working. You should call the dentist.")

_The Portable Pediatrician_, a guide for parents about children's health and development, includes a lot of advice about when to take a baby to the doctor, or when to phone the doctor. The book regards "child smells sick" as something to consider and take seriously. The author writes as if parents are aware of how their babies and toddlers usually smell and notice sudden changes without particular effort, the same way they're aware of their children's usual sleep habits and notice if those change drastically. Smelling sick can be one of the early symptoms, before fever. As you say, it can also happen the other way around, where a person is horribly sick for days before noticing he smells sick.

>But how would you pass the knowledge on to another generation? I mean, for common things, sure. "Okay, this is what a basic fever smells like." But that's not really THAT useful.

It depends how you define "basic fever." With antibiotics available, the important distinctions are "is it likely to be contagious?" and "is it the kind of bacterial infection that antibiotics can cure?" (A large enough collection of bruises will make me run a fever. Is that "basic?") Questions like "does the person have trouble breathing?" and "is the person's digestion working well enough for them to avoid dehydration?" are really, really, important, but don't depend on what caused the illness.

[sashajwolf.livejournal.com]

This is not going to be my most informative comment ever, but ISTR that some group of scientists tried to create an "artificial nose" to detect certain kinds of disease; my memory tells me it was lung disease, possibly TB, but I don't remember. I didn't hear any more about it, so I assume it didn't work out.

[jehanna.livejournal.com]

It would make sense that many cultures would have used and passed on this knowlege--I think it would work the way much learning did before writing was widespread; you would learn at the side of a practitioner, and that way you'd remember the smells.

Hormones have a definite effect on scent, obviously. Having been able to compare the "before" and "after" of taking estrogen on a person, it's easy to tell the difference.

[redknight.livejournal.com]

I believe smell plays a part in the diagnostic process used in traditional Chinese medicine.

[vvalkyri.livejournal.com]

I seem to recall Chinese medicine involves smelling breath as one of the diagnostic tools.

[redknight.livejournal.com]

That reminds me, fruity smelling breath is one of the symptoms of diabetic ketoacidosis (http://www.nlm.nih.gov/medlineplus/ency/article/000320.htm).

[linenoise.livejournal.com]

I know that one of the important ways that I can tell the difference between "really bad allergy attack", "random virus", and "something's infected, break out the antibiotics" in myself is the way that my saliva tastes. Random virus can often have almost the same symptom profile as allergy attack, and a sinus infection or bronchitis has significant overlap as well.

But they *taste* different. Which, I assume, means that my breath probably smells different, too.

[thnidu.livejournal.com]

dunkelpig usually knows that I have a sinus infection before I realize it. She smells it in my breath.

But how would you pass the knowledge on to another generation? I mean, for common things, sure. "Okay, this is what a basic fever smells like." But that's not really THAT useful.

Apprenticeship! Seven years or whatever training under the healer, helping out, accompanying him or her around. That won't pass on all the experience, but a lot of it. And "This person has X; smell the nose breath, not the mouth breath. Old So-and-so had Y, and his nose breath smelled something like that, but sharper, with a little bit like a red ants' nest; and he didn't have this yellowy thin goo in the corners of his eyes."

[kalmn.livejournal.com]

yet another fine application of this under utilized technology:

http://mfrost.typepad.com/cute_overload/2007/01/yep_you_take_a_.html

[ellettra.livejournal.com]

interesting post. i was just commenting to shanon the other day that i don't know if it's the residual sickness still in my throat, or if it's the antibiotics, but i have noticed a different smell, too. it was kinda freaking me out, so i started pounding the water, but it's still there, only less powerful. i am less freaked out knowing other people experience this as well, though. :) i can always tell when shanon's blood sugar is high - she has a very distinct smell when it gets high, and when it gets *very* high, it's almost overwhelming. i can predict my own menstrual cycle by the way my breath changes, as well.

it's all highly interesting.

[hel]

I recall reading an article about animals being trained to smell disease, but my google-fu is failing me, I can't find it.

[felis-sidus.livejournal.com]

Ayurvedic physicians include the use of smell in their diagnostic procedures, but don't rely on it alone. This is true of a number of approaches to medicine, as others have commented. I'm not aware of any method that relies on the use of smell alone.

[angelovernh.livejournal.com]

Wait, you're saying the pregnant person can smell the diseases or that other people can smell if someone else is pregnant? I thought you meant the former, but then you said your father could, so I think you meant the latter.

I do think that my dog can smell that I'm pregnant and it may be affecting her behavior. Aramis thinks so. The vet had NO idea if there was any correlation. :eyeroll:

Yes, I think that smelling illness is probably what some tribal healers did.

[xiphias.livejournal.com]

My father can smell if someone is at a certain stage of pregnancy. That's what I meant. I don't know whether pregant people would be better at smelling disease, but it would't surprise me if it were true -- that seems like a useful evolutionary adaptation.

[mswae.livejournal.com]

There was an article in a recent NEJM bemoaning the loss of teaching diagnosis by smell to medical students. So far, no clinical training (ask again in six months) so I don't know if they teach it here.

[baratron.livejournal.com]

Apparently there exist assistance dogs who can smell when an epileptic is going to have a fit, so the person can make sure they are somewhere comfortable and not holding sharp objects, etc. But this is just something I remember reading about once.