Why do we sweat? Of course there are the obvious reasons—excessive heat and physical activity—but what else can trigger sweating and can we stop it?
We’ll explore everything you’ve ever wanted to know (or not!) about sweat on this page, including:
- What sweat is and how it leaves your body
- What causes you to sweat
- What causes body odour
- The difference between regular and excessive sweating
- How to stop sweating
What sweat is and how it leaves your body
When you sweat, the sweat leaves your body through your sweat glands, which are tiny pores in the skin.
Who would have thought that we have millions of sweat glands all over our bodies? While men and women have the same number of sweat glands, the size of each gland, and the volume of sweat they produce, is approximately five times greater in men.
Sweat is mostly made up of water, but it does contain some salts and sugars—such as sodium, chloride and potassium—as well.
There are two types of sweat glands—eccrine and apocrine:
- Eccrine glands occur all over the body but you’ll find more of them on your palms, on the soles of your feet and on your head, which makes sense if you think about where you sweat the most when you’re hot!
- Apocrine glands are present in the armpits, groin and other areas in which there are hair follicles. Sweat from the apocrine glands is thicker than eccrine sweat and is triggered when you’re stressed. Unfortunately, bacteria love to eat the nutrients in apocrine sweat, which is why you might notice an unpleasant odour whenever you’re in a stressful situation.
What causes you to sweat
Sweat can catch you out anywhere. You may sweat when you’re at work, at home, during hot weather or even when you’re having fun and relaxing on holiday. It’s not unusual to feel much too warm on crowded trains or in busy offices, and (we hate to say it!) you can start to become very sweaty in these situations.
When you start feeling too hot—whether from warm weather, exercise, stress or maybe indulging in certain food or drink—your brain tells your body that it’s overheating. When this happens, your millions of sweat glands send moisture—sweat—out onto your skin to cool you down. But the good news is, when you slow down your activity and your body temperature drops, you’ll feel much less sweaty.
Below we take a look at the four most common sweat triggers:
A strenuous workout for one person can be a light warm-up for another. However, when your body deems a workout to be tough, your temperature increases. Whether you’re powerwalking or sprinting, your body will find a way of getting rid of that extra heat through sweating.
If you sweat a lot when you exercise, it’s not because you’re unfit. In fact, it’s quite the opposite.
Your body is so familiar with working out that it knows it needs to cool off—pretty clever, right? By regularly keeping fit, your body will have adapted to your training and will recognise when it needs to try and lower your temperature so you can exercise for longer.
Naturally, when the temperature rises, you perspire. While sweat can leave your skin feeling wet and uncomfortable, it’s the body’s way of cooling down. Not ideal if you’re on the beach, but sweating from the heat is totally natural, totally normal and a good excuse to get a lovely cool drink!
You’ve probably noticed you start to sweat when you’re stressed. Whether you’re feeling angry, scared, embarrassed or anxious, a stressful situation can worsen if you’re conscious of how much you’re sweating.
Sweaty palms (or sweat anywhere!) when you feel stressed is completely normal. If you know you’re going to be in a stressful situation, why not prepare ahead with a spritz of anti-perspirant when you’re getting ready?
If you’ve ever experienced beads of sweat on your forehead while eating a fiery curry, you’re not alone. Spicy foods activate the receptors in the skin that react to heat, so to compensate your body will naturally try and cool itself through sweating.
The body reacts in the same way towards caffeinated drinks and alcohol. Both of these substances cause the blood vessels to widen, which, in turn, can cause us to sweat.
Although it’s important to stay hydrated, drinking too much water can actually make you sweat more as your kidneys have to work harder to get rid of the excess fluid.1
Hot and cold sweats and why they happen
It’s not always exercise, the weather, emotions or what you eat and drink that makes you sweat. Sometimes, you might find you sweat for no obvious reason. Hot sweats and cold sweats are both different to regular sweating.
Hot sweats (also known as hot flashes or flushes) are sudden and intense feelings of body heat that cause sweating. They are usually harmless and can be triggered by anything from stress or fever to the menopause or as a side effect of taking certain medication.2
Hot sweats or flushes are often accompanied by night sweats. Night sweats can also be a symptom of the perimenopause and the menopause, but can also happen after having a baby. In both cases they occur due to low levels of oestrogen.3, 4
If you experience hot flushes or night sweats regularly, it’s always best to discuss your symptoms with your GP. They can give you advice and possibly diagnose any underlying condition that might be responsible.
Cold sweats often occur when your body enters ‘fight or flight’ mode as the result of being stressed. If you’ve ever suffered severe anxiety or had a panic attack, you’ll be familiar with this experience. Anxiety can raise your body temperature and increase your heart rate. This sends a message to your sweat glands to let them know they need to produce sweat to cool you down.
Cold sweats can be caused by low blood sugar levels (for example, if you’ve skipped a meal), as a lack of glucose in the blood can trigger adrenaline to keep you going until the next time you eat.5
Other causes of cold sweats include:
- side effects from medication6
- thyroid problems7
It’s always a good idea to check the cause of cold sweats with your GP to rule out any underlying health issues.
Causes of body odour
Contrary to what you might think, body odour doesn’t come from sweat itself. The bad smell is actually a result of bacteria breaking down the sweat molecules into fatty acids and releasing a pungent odour.
Body odour is unpleasant (and sometimes embarrassing), but it’s absolutely normal and easily prevented. So, how can you ensure that this bacteria doesn’t build up?
Go easy on alcohol, caffeine and strong-smelling food
When it comes to cooking, as much as you may want to add flavour to your food in the form of garlic or spices, it’s important not to overdo it. These ingredients release gases that contain sulphur. When your body breaks them down, it causes an unpleasant smell.
A strong coffee in the morning or a G&T in the evening may seem like a perfect pick-me-up, but caffeine and alcohol can make you sweat more. Alcohol enlarges the blood vessels, which can cause you to sweat9. Your body excretes some types of alcohol through your sweat, so your sweat might actually smell of what you drank the night before! 8
The caffeine in your favourite coffee could actually be making you sweat more, and making that sweat smell unpleasant. Caffeine stimulates the apocrine sweat glands, which are responsible for producing the type of sweat that causes body odour9.
Maintain a good personal hygiene routine
Showering and bathing every day, especially after a workout or a stressful situation, can help to keep you smelling nice.
Apply anti-perspirant and/or deodorant
Anti-perspirant helps to prevent the amount of sweat you produce, while deodorant kills the bacteria that causes the unpleasant smell. By using either anti-perspirant or deodorant, or applying a product that contains both, you can limit how much you sweat and help prevent body odour.
Soft & Gentle’s Skin Protect range offers up to 48 hours of sweat protection and comes in a range of gorgeous fragrances, including Orange & White Ginger and Sheer Rose & Lavender.
To find out more about the best way to apply anti-perspirant or deodorant, read our guides:
- How to use deodorant
- How to apply anti-perspirant for best results in our guide Anti-perspirant—How to choose and apply the best one for you
For more tips on how to reduce the amount you sweat, read What is excessive sweating and what can I do about it? in our article How does anti-perspirant help prevent sweating?
The difference between regular and excessive sweating
Sweating is your body’s way of controlling its internal temperature. Everyone does it and it’s completely normal.
Although there are no guidelines that define what ‘normal’ sweating is, if you’re conscious of the amount you sweat and find that excess sweating is having an impact on your day-to-day life, it might be worth checking in with your GP.
Your GP will determine whether you have hyperhidrosis, the medical term for excessive sweating. They might recommend you use clinical-strength anti-perspirant or make certain lifestyle changes, such as avoiding certain foods and wearing loose clothing made of natural fabric.
How to stop sweating
Although you can’t actually stop yourself from sweating completely, one of the most effective ways to help reduce how much you sweat is to apply anti-perspirant. Anti-perspirant products have active ingredients that react with your sweat and block your sweat glands. This means less sweat makes it to the surface of your skin.
If you want to find out more about how anti-perspirant works to stop sweating, read our in depth guide How does anti-perspirant help prevent sweating?
How to reduce armpit sweat
There are around 25,000 sweat glands in each armpit and these can produce roughly 1.5ml of sweat every 10 minutes10. While this is only a small number of your glands, sweat is more noticeable under your arms as it’s more likely to get trapped there.
Sweat patches under your arms can be more obvious with some outfits and make you feel self-conscious—not what you want from your day!
You can’t stop sweating completely, but there are a few ways you can tackle underarm sweat:
- Anti-perspirant—using anti-perspirant is the first port of call for reducing armpit sweat. Apply it after showering and before you go to bed to give the active ingredients enough time to get to work blocking your sweat glands.
- Wear light clothes—dressing in loose clothing made of lightweight cotton or linen can help a lot. They’re the most breathable, natural and stylish fabrics around and they absorb moisture rather than resist it. So not only will you look comfortable and fashionable, you’ll feel it too!
- Shave your armpits—whether you do this is, of course, a personal choice. But if you find you’re prone to sweating, shaving under your arms could make your anti-perspirant more effective, as its active ingredients can more easily reach your sweat glands11.
You can find out more information about how to prevent sweating in other areas of the body with our guide Where on your body you can use anti-perspirant?
For more information on how anti-perspirant works, read our guide How does anti-perspirant help prevent sweating?