Experienced a few clammy encounters? Sweating is oh-so-normal, particularly in summer. But if your clothes are drenched when it’s cold outside, there could be an underlying health reason that needs addressing. Find out what could be causing your excessive sweating, and what you can do about it.
Why do we sweat?
Before you get self-conscious about sweating, you should know that everybody sweats. We actually need to sweat to help regulate our body temperature. If we didn’t sweat, then our bodies wouldn’t be able to cool down and we’d overheat, and that can lead to heatstroke, which can be fatal. Sweating — also known as perspiration — is your body’s clever way of cooling you down when you get too hot.
When your body temperature rises, sweat is released through ducts in your skin. It moistens the surface of your body and cools you down as it evaporates.
Sweat is mostly water, but about 1 percent of sweat is a combination of salt and fat.
There are lots of things can cause you to sweat — hot weather, exercise, spicy foods, medications, hormones, certain illnesses, fever, even stress and anxiety can make us sweat more than normal. But for the majority of people, sweating is a result of rising temperatures. When temperatures rise — be that from the weather or from exercising in the heat — the sweat glands kick in to produce more sweat.
This is why we sweat more in summer, because the weather is much warmer than usual.
Your body responds pretty quickly. More often than not sweating comes and goes fleetingly — we sweat, we cool down, we stop sweating. Other than perhaps a damp shirt, or a few unsightly sweat patches under your armpit, once your body has cooled down, you’ll dry off your sweat patches under the hand drier and carry on as normal, forgetting that it even happened.
But for some people, it’s not just the heat that causes them to sweat. It’s actually your central nervous system at work without you even realising. It’s responding to stimuli such hot weather, stress, exercise, medication (among others), to trigger your sweat glands to produce water (sweat) to cool your body down.
It’s actually out of your control as to how much your body sweats, or what triggers that sweat response. That means that some people sweat more than others, and for a number of different reasons.
Where do we sweat?
Sweating, also called perspiration, is the release of a salt-based fluid from your sweat glands. When our skin develops moisture on the surface, that moisture is evaporated and cools the skin.
Sweat glands are found all over the body — the average person has between 2–4 million eccrine sweat glands; these make up the majority of sweat glands, and are largely found on the soles of the feet, palms, the forehead and cheeks, and armpits.
Eccrine glands secrete an odourless, clear fluid (water and electrolytes) that helps the body to control its temperature by promoting heat loss through evaporation. These glands respond primarily to rises in body temperature.
The other type of sweat gland is called an “apocrine” gland. Rather than responding to rises in temperature, apocrine glands often respond to emotional stimuli including anxiety and fear. These are the glands that can produce body odour.
Apocrine sweat glands are commonly found in your armpits and groin area. They produce a thicker type of sweat that produces an odour when it comes into contact with bacteria on the skin’s surface.
Both eccrine and apocrine sweat glands are activated by your nervous system, but as we mentioned above, they can be triggered by a number of different factors, including:
- messages from the brain indicating that the body is too hot
- emotions (stress, anxiety)
- physical activity or exercise
- diet — particularly spicy foods, caffeinated drinks and alcohol
- illness or fever
We're all born with practically the same amount of sweat glands, but as we age, our sweat glands change; they stop working as effectively as they did when we were younger. Our bodies aren’t able to regulate high temperatures as well as they once did. This is why you’re more prone to heat-related illness if you’re aged 65 or over.
But sweating can also differ from person to person depending on your fitness level — sweat glands are more active in fitter people — your muscle mass, your metabolism, and your body size. People who are overweight or obese tend to sweat more because they have to move more body mass, and that means more heat generated and more perspiration in order to cool their body down.
So what’s considered normal sweating and what’s not?
The sole purpose of sweating is to cool your body down when it gets too hot, so the amount of sweat you produce really depends on the demands of your body and what you’re doing. For example, if you’re exercising or undertaking manual labour in a hot environment, then your body is going to sweat more than normal.
Similarly, if you become nervous or anxious, you’re likely to sweat more. It’s your body’s response to stress. When we’re nervous or anxious our bodies tend to overheat, so this response is your body’s clever way of cooling you down. Whether you like it or not. We know all too well how awkward those nerve-wracking/clammy interviews can be.
Whilst a number of different factors can trigger sweat glands to perspire, in some cases, people can sweat uncontrollably for no apparent reason. This is known as excessive sweating, or hyperhidrosis.
As many as 3 in every 100 Australians suffer with excessive sweating. With hyperhidrosis, people sweat profusely outside normal scenarios — like overheating, exercising or anxiety. For example, it’s not considered normal to produce a lot of underarm sweat in mild heat.
Often people with hyperhidrosis can sweat so much that it soaks through their clothes, which can be both distressing and embarrassing.
If you suffer with hyperhidrosis, the sweating can either occur:
- in certain areas of the body, usually the armpits, hands, feet or face, which is known as focal hyperhidrosis — this is usually as a result of overactive nerve functions, and this tends to run in families.
- in the entire body, known as generalised hyperhidrosis — this type of excessive sweating is usually due to an underlying medical problem.
So what causes excessive sweating?
Sweating normally occurs when the nervous system triggers the sweat glands to produce sweat to cool the body down from high temperatures, exercise or stress.
With hyperhidrosis, sometimes, the nerves become overactive and trigger the sweat glands to produce fluid even without exposure to heat or partaking in physical activity. It’s often worse if you’re nervous, anxious or stressed, and it tends to run in families.
But there are also some medical conditions that can trigger excessive sweating.
- thyroid problems
- low blood sugar
- some types of cancer
- heart attack
- nervous system disorders
Some medications can also cause you sweat more than normal, these include some beta blockers and antidepressants, pain medications, blood pressure and cardiovascular drugs, chemotherapy, hormonal treatments, diabetes medications and nerve pain treatments.
If your sweating is causing you concern, or having an effect on your professional or personal life, there are treatments available to help.
These can include:
- a range of psychotherapy, behavioural therapy and relaxation techniques to help reduce anxiety.
- antiperspirants, nerve-blocking medicines, antidepressants or botox (botox works by reducing the amount of sweat produced by sweat glands when injected around the glands).
- Iontophoresis — a mild electrical current is delivered through water to areas of affected skin.
- as a last resort, your doctor may recommend surgery to remove the sweat glands or sever the nerves.
Visit your GP who will examine you and run some tests to rule out a medical cause of your excessive sweating.
Here are 7 other surprising reasons that can cause you to sweat more than usual:
2. Overactive thyroid
Your thyroid gland plays a large role in controlling your body's metabolic rate, so when it goes into overdrive, it produces excess levels of thyroid hormones that also affect your body temperature. When you produce too much of these hormones, your body tends to overeat and you sweat more as a result.
3. Menstrual changes
Women have to cope with a rollercoaster of hormones during and after their periods, so often rises and falls in oestrogen, progesterone, and other female hormones can sometimes cause core body temperatures to rise. For some women, this can cause more sweating closer to their period or a few days before.
Perimenopause — the period of time just before the female body enters menopause and stops having a menstrual cycle — causes excessive sweating much the same as pregnancy, as your body is experiencing fluctuating hormone levels. Oestrogen in particular has an effect on your body’s temperature, so when it rises during perimenopause, so can your body temp.
People with diabetes are often more prone to sweating. This is because when your blood sugar drops too low, you produce excess adrenaline, which causes sweating, mainly at night (night sweats).
Diabetics are also more sensitive to certain foods, so are more prone to gustatory sweating — sweating that occurs on the forehead, scalp, neck, and upper lip while eating, talking, or even thinking about food. This is, however, rare and only associated with serious diabetics who may have suffered nerve damage.
6. Increased metabolism
Noticed you’re sweating more after a big meal? This is because your metabolism is kicking into gear, and a by-product of increased metabolism is heat. Your body therefore produces sweat to cool itself down. You shouldn’t worry too much about this — just relax after dinner and you should feel better (and less clammy) fairly quickly.
Perhaps not the best gift your parents could give you, but in many cases, excessive sweating is actually purely down to genetics. People are born with it. But of course, sweating can also be connected to your hormones, underlying health conditions, and some mental health issues, so if it's becoming a problem for you, you should visit your GP for further advice.
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