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    Body odor: What causes body odor and how can you prevent it?

    Updated 23 January 2023 |
    Published 13 December 2022
    Fact Checked
    Medically reviewed by Dr. Sarina Schrager, Family physician, professor of family medicine and community health, University of Wisconsin-Madison, Wisconsin, US
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    Growing up, your period, and the stress of asking your crush out — there’s a lot that can impact how much you sweat and, more importantly, how it smells. Here, a Flo expert busts some of the myths linked to body odor and shares some tips to keep it under control. 

    Body odor (or BO as you might better know it) is a totally natural and normal part of growing up, but that doesn’t mean it’s not annoying. You’re showering as much as you ever did and using your favorite fruity soap. But suddenly your parents or friends are dropping subtle hints that they can smell the funk coming from under your arms. 

    Puberty can be daunting enough as it is, so new and not-so-welcome smells are probably the last thing you want. You’re already busy getting to know your menstrual cycle (by the way, you can track that using an app like Flo) and watching your body change in ways you might not have expected. 

    Here, Flo expert and general practitioner Dr. Amanda Chisholm, United Kingdom, gives us the lowdown on BO, as well as some handy tips and tricks to prevent it. 

    What causes body odor?

    First things first, what actually causes body odor? You’ll know from gym class that you sweat when you were a kid. So, why does it smell different now? 

    To deal with body odor, you need to know where sweat comes from. You might have always thought that all sweat is made in the same place. But there’s actually a little more to it. Your sweat is produced in two different types of glands, and they work in different ways. 

    Your eccrine glands: Your eccrine glands are found all over your body — from your armpits and forehead to the soles of your feet. These are the sweat glands that work to keep your body cool when you’re working out or too warm. Sweating is a totally natural process. When your internal temperature starts to rise, it triggers your sweat glands to start to produce moisture to cool you down. And when your body produces this type of sweat, it doesn’t smell. 

    Your apocrine glands: Your body is also covered in apocrine glands that produce sweat (many of them are found in your groin, under your arms, and on your feet). 

    If you’ve ever noticed that you start to feel wet patches under your arms when you’re put on the spot in class, then you’ll know that nervousness and excitement can also trigger sweating. Your apocrine glands are triggered by strong emotions like fear or anticipation. When sweat produced in these glands comes into contact with natural bacteria found on your groin, armpits, and feet, it can start to smell.

    The bacteria that sweat from your apocrine glands comes into contact with is slightly different from person to person, meaning your BO is likely to smell a little bit different from your best friend’s. Read on to learn why your BO might smell how it does. 

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    What may cause body odor change?

    “We all know roughly what body odor smells like, but yours is unique,” explains Dr. Chisholm. “It’s not the sweat itself that smells, but when it’s combined with bacteria, that’s what produces the smell.” 

    Puberty is just one reason your body odor might change. Changes in your hormone levels, your period, and different medical conditions can all impact the way your sweat smells. Let’s learn a bit more about why.


    If you’re reading this, you’ll probably have noticed a bit of a change in the way you smell.

    There’s actually a really simple explanation for this. During puberty, the amount you sweat will change, and this affects your body odor. This is because the apocrine glands (remember, those are the sweat glands that respond to emotional stressors) switch on during this time due to changes in your hormones.

    “You have sweat glands all over your body, but when you’re younger, they don’t function so well, so you don’t produce as much sweat,” explains Dr. Chisholm. “When you go through puberty, your hormones switch on these sweat glands so that they can fully function, and the chemicals in your sweat also change. It’s a normal process, and everyone goes through it. You will find that you sweat more, and the odor that comes with it is natural.”

    A change in the way you smell is likely to be just one of many changes you’ve noticed about yourself lately. Apps like Flo can help you bust some of the myths linked to puberty. 


    Along with mood swings, body odor isn’t only a common sign of puberty. It can also change throughout your menstrual cycle. 

    “A lot of the things that govern how the body works are often hormone driven,” says Dr. Chisholm. This can affect your body temperature, for example, and if you’re hotter, you’re likely to sweat more, causing more body odor. “Temperature fluctuations aren’t uncommon at different times of your cycle,” she says. 


    As we found out earlier, sweat can be an emotional response as well as your body’s cooling mechanism. 

    Your teen years are a time of first crushes, big tests, college applications, and more. You’re figuring out who you are and who you want to be, and that comes with a fair amount of stress. 

    You’ve probably noticed that when you’re feeling nervous, excited, or scared, you get sweaty palms or underarms. This is because in moments of high emotion, our bodies can go into “fight-or-flight” mode — a high adrenaline state of being that’s designed to prepare us to act if we’re in danger. 

    When you’re in fight-or-flight mode, your muscles can become tense, your heart rate quickens, and you will sweat more. This would have been perfect for our prehistoric ancestors who were readying themselves to fight a bear. It’s less useful when you’re working yourself up to ask your crush to prom. 

    Food and drink

    It isn’t just hormones that can impact the way our BO smells. Dr. Chisholm explains, “What you eat and drink can come out in your sweat through your pores. That’s because sweating, like going to the toilet, is also a way to get rid of waste.”

    Now, you don’t need to worry too much about the effect of that family-size bag of cheese puffs. However, there are some foods that have been linked to body odor. These include: 

    • Garlic
    • Red meat
    • Onions
    • Broccoli

    Similarly, you might be able to blame a change in the way you smell on your favorite iced latte or energy drink. This is because caffeine can trigger body odor. Drinking alcohol can also impact the way you smell. (But this will only be something you have to think about once you’re old enough to drink, of course.) 

    Medical issues

    Sweating might also be a sign that you’re experiencing an underlying medical condition. Liver disease, diabetes, and kidney disease can change the way your sweat smells. 

    If you find that you’re sweating during the night or when you’re sitting still and feeling calm, then speak to your healthcare provider. There’s no such thing as an embarrassing or silly question, and they should be able to put your mind at ease. 

    One of the most common reasons this might be happening is if you’re taking medications like pain relievers, antidepressants, or some diabetes and hormonal medications.


    Pregnancy might not remotely be in your plans right now but, just like puberty, it’s a time of massive bodily and hormonal changes. “You can sweat more when you’re pregnant because you’re carrying more weight around and you may get hotter,” says Dr. Chisholm.


    Menopause might feel like a very distant experience too, but it’s really good to be clued up on the way your body changes later in life. One of the most common side effects experienced by people who have transitioned into menopause is night sweats and hot flashes. Menopause happens when you have a stark drop in your estrogen levels and your period stops. 

    Common body odor treatment solutions

    Body odor and sweating can feel embarrassing, but there’s no need to feel like that. They’re something everyone goes through, after all, and it’s totally healthy to sweat. 

    Luckily, there are so many ways you can treat body odor.


    If you’ve noticed a new tangy smell coming from your armpits, Dr. Chisholm says the first step is to “make sure you wash your body at least once a day and your armpits, groin, and feet twice a day.”

    The doctor also recommends using gentle products that aren’t perfumed to avoid irritation, which could make you sweat more. Looking for soaps with antibacterial properties could be a really great idea. 

    Change your clothes and wear natural materials

    Another way you can help to keep BO under control is by changing and washing your clothes regularly. For example, it’s good to change your socks regularly and not wear the same pair of shoes every day so that they can dry out completely, says Dr. Chisholm. It’s also wise to wear cotton or wool socks instead of synthetic materials that could cause irritation and sweat buildup. 

    The same goes for your underwear, as the bacteria in these areas are very sensitive and can be affected by different materials. It turns out cotton underwear might not only be seriously comfortable, but good for you too. 

    Deodorant or antiperspirant?

    Roll-on, stick, or spray? Fresh linen, flowery meadow, or cucumber hibiscus? The choices of deodorant and antiperspirants are endless. But there is an important difference between the two. 

    Deodorant gets rid of the smell, while antiperspirant works to reduce sweating as well, although it can’t stop it entirely. “Sweating is a helpful [bodily function],” says Dr. Chisholm, who recommends using deodorant day to day. 

    In terms of finding the right deodorant — spray, roll-on, or solid — that’s down to personal preference. Whatever works for you!

    Natural deodorants 

    Deodorants made from natural ingredients, such as herbs, oils, and baking soda, are becoming more and more popular — and are often less irritating on the skin. That’s because a lot of traditional deodorants contain aluminum, which can make your skin feel itchy and sore.  

    Natural deodorants won’t stop you from sweating. Instead, they work to minimize the odor. They tend to include ingredients with disinfectant or antibacterial properties, such as tea tree oil, and/or essential oils such as lavender to create a nice smell. They also have naturally absorbent ingredients like baking soda or cornstarch to combat moisture. 

    Foot powder

    Because your feet are stuck in shoes most of the time, when you sweat, it has nowhere to evaporate, and this can cause body odor. Foot powders can be bought to absorb sweat.

    Medical intervention

    If you’ve tried everything and feel totally out of ideas as to how you can manage your BO, then don’t be afraid to speak to your healthcare provider about it. There’s no such thing as an embarrassing question; sweating shouldn’t affect your quality of life. 

    Your doctor may be able to offer you

    • Medication that reduces the amount that you sweat 
    • A suggested change in your diet (to cut out the foods that could be changing the way your sweat smells)
    • Antibiotics to reduce the levels of bacteria on your skin
    • Injections of botulinum toxin to temporarily block sweat

    Generally, your doctor will only recommend these procedures in severe cases. The BO that you might typically experience during puberty wouldn’t normally need this much medical attention.   

    Stay hydrated and healthy

    Lastly, the best thing you can do to keep your body healthy, happy, and smelling sweet is by drinking lots of water.

    Body odor: The takeaway

    Although it can feel uncomfortable and sometimes a bit embarrassing, Dr. Chisholm has some good advice: “Just remember that body odor is completely normal. It comes from sweating, which is a really helpful thing,” she says. “If the smell bothers you, there are things you can do about it. Everyone goes through it, and it’s normal for the rest of your life.”

    If you’ve tried a different deodorant, change and wash your clothes regularly, and shower lots — but you’re still noticing an unpleasant smell — then don’t be afraid to speak to your health care provider or a trusted adult. 

    Chatting about BO over your morning cereal might not sound very fun, but you deserve to be comfortable and have the help you need.


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    History of updates

    Current version (23 January 2023)

    Medically reviewed by Dr. Sarina Schrager, Family physician, professor of family medicine and community health, University of Wisconsin-Madison, Wisconsin, US

    Published (13 December 2022)

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