When kids are little, they don’t usually have body odor even if they run around and get sweaty. But when people become teenagers, suddenly they can smell bad if they don’t shower. Why does this happen? What changes in the body that causes the smell to start?
Ps: I know hormones is a factor but I would like a deeper explanation.
Edit: I know the basics, but I was hoping for a deeper dive into the why of it all in simple terms. I’m trying to learn more, not just get the quick answer. Thanks to those who gave more context!
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Specifically, in puberty the apocrine sweat glands are activated, which produce sweat with fats and protein which secrete a stronger odor when in contact with air.
There are eccrine and apocrine sweat glands are the things to look up for more. As you get into puberty you have more active apocrine glands. They release proper food for bacteria in a thicker secretion. The bacteria eat it and their byproducts smell.
In sex ed you are taught about puberty and the fact that during the process your body produces more sweat
The sweat is produced often enough that it combines with bacteria and let’s them grow, creating many gross biproducts that smell
Think of it like this:
Pretend you were hairless until you hit puberty. Then slowly you started growing small amounts of hair until you grew lots.
Now pretend there are bugs that only live in hair. That’s why it is that way.
Bacteria that produces smells live off of the stuff your adult body produces a lot of, but your child body produces much less of.
Also there is a quantity factor. If you leave a dirty plate and cup in your sink, it won’t smell too much. Leave two sink-loads full of dirty dishes, half full of water and rotten food, and it will smell like hell.
Kids also produce stuff that can make them “smelly,” but not all the same things as adults nor do they produce as much.
Most of the worst smells come from the bacteria eating your sweat, oils, dead skin, etc, and producing their own waste. Kids just don’t produce as much of this bacteria food, so it can take longer to build up before they stink, plus our “cocktail” of secretions gets a little more complex after puberty.
It’s related to why we get acne breakouts, too: the body producing a lot more sweat/oil and the pores get clogged.
Ok but what about when you’re old? How is it i smell an “older” person as a distinctive smell? Am I gonna smell “old” even when I shower?
Aparently you haven’t smelled my four year olds feet after a day at school
I noticed I had a terrible time smelling good even after barely sweating. It’s only in the last few years of my life I realized when I’m stressed, nervous or just uncomfortable my sweat smells like BO. I was continually stressed, nervous and uncomfortable every day all day for years in school. I had no idea until recently when I went long periods of time even sweating a little and not having any kind of BO smell.
Honestly little kids stink to high heaven imho but not in the underarm BO way but they’re definitely super stinky
First of all, you should know that there are both eccrine and acrine glands. When we are small children, only one type of sweat gland functions (the eccrine glands) which produces sweat almost exclusively from water and salt, so it doesn’t smell bad. But at puberty, hormones activate other glands (the apocrine glands) that produce a different sweat, full of fats and proteins. This new sweat does not smell by itself, but bacteria on the skin feed on it and, by breaking it down, release substances that smell bad.
Clearly you’ve never smelled the things that can accumulate in the many rolls of an infant 😩 one of the most disgusting things I learned very quickly as a new parent was to get into those nasty folds in order to clean the cheese and lint out 🤢
Frankly I find the smell of sweaty elementary schoolers to be nauseating. It’s very different from pubescent humans, but they definitely have a distinct type of overall BO.
Because teenagers overwash themselves. Kids don’t need bathing daily or washing with soap, just a quick rinse is all you need. Sweat in general is odorless but when you strip away your natural oils by soap/body wash, bad bacteria accumulates and causes bad odor.
Sex scent signaling that this person is an adult or on the way to being a hairy stinky horny adult. Hormones make people smelly.
Apparently (I haven’t bothered to confirm this) the role of male post pubescent B.O. is to scare away females that are not ovulating. If true that would explain why younger kids don’t get it.
Oo since we are on the topic of bo, can someone explain why old people do too? For old people its def not bo considering they all smell exactly the same whereas bo differs from person to person
It has to do with apocrine sweat glands that get active during puberty. They produce a type of sweat containing fat and bacteria break it down into smelly substances. Without these bacteria it wouldn’t produce the smell. Some time ago I had to wash myself with chlorhexidine after a skin infection and suddenly all my BO disappeared as a side effect. My sweat became completely odorless (not just to myself), even without deodorant and after exercise. A week after stopping with the chlorhexidine it went back to normal.
Two kinds of sweat glands. Eccrine are basically just salty water and all over. Nothing for bacteria to eat. Apocrine is mostly in the pits and groin where there is more hair (and scalp, and some upper back) and also leaches out oils and proteins, which bacteria eat and their waste products can smell. Apocrine turns on when you’re a teenager, it’s a hormone signal.
Some people have genetics where the apocrine glands don’t really turn on as much and there is less bacteria food in the mix, so they don’t tend to smell as much. It is linked to the gene set that tends to make earwax dry and flaky instead of gunky.
Why do we have apocrine glands?
A couple of ideas – one is that they are remnant of pheromone signaling that we no longer do as much.
Another is that they help to repel water from protective hair by coating the hair in fat. This is interesting because it follows that apocrine glands are a bit concentrated on the scalp and upper back, where (if we were hairier) would work to keep us dry in the rain and protect us. Perhaps our ancestors were hairier on the head, neck and upper back and shoulders where sun exposure is the strongest, and then less hairy on other parts to help with sweating.
Another is that they help with sweat ‘sheeting’, which improves the sweat’s ability to disperse, evaporate and cool.
Another is that they help to lubricate hairs that act as friction reducers in skin folds.
But that fatty secretion is bacteria food, so to stop it you 1) clean yourself regularly to remove bacteria, their smelly byproducts and the fatty food, 2) use deodorant, which has a chemical that fights bacteria, or 3) use anti-perspirant, which also plugs up those glands and reduces their output of bacteria food.
Have you never smelt a sweaty kid after they woke up Jesus Christ
Sez who?
Little kids smell different. But, trust me, they can be plenty odoriferous. That said, sense of smell can be somewhat surprisingly subjective. Particularly in assigning a value to a scent. The same scent could be pleasant to some and deeply unpleasant to others.