Sweating: And all the small stuff!


The skin is a complex organ, containing three layers. The outer layer is the epidermis – which sits on the skin surface, the dermis is deeper down, and the hypodermis is the deepest layer of skin. The dermis sits about 0.5mm under the epidermis, and is around 2-3 mm thick. It contains may important structures, including hair follicles, collagen, elastin, blood vessels and hyaluronic acid. Sweat glands are also located in the dermis. Sweat glands occur over the entire body, but are most concentrated on the face, under the arms, the palms of your hands and soles of your feet. We have around 3 million of them, and there are two types: Eccrine and Apocrine glands.

Eccrine glands produce a clear, odorless fluid as part of body temperature regulation. However there is also another type of gland, call the Apocrine gland. These sweat glands are most concentrated in the hair follicles of your scalp, armpits and groin. These glands carry a distinct odour, as the excretion from these is heavier and composed of an oily-substance. So the smelly kind of sweat happens when the apocrine glands release the fatty-secretions which then mixes with bacteria on the skin.

Sweat mainly consists of water (and fat in the Apocrine glands), but will also contain some salts. Sweat is an important bodily function, mainly for the purpose of cooling our body down. This can occur when our core body temperature rises due to exertion, the ambient air temperature rising, emotional stress, eating spicy foods and also when we are fighting infection. As the sweat evaporates from our skin, our body will feel cool to the touch.

Sweat quantity can differ amongst people greatly, and can also be influenced by hormones too. Some people will worry that they have excess sweating, but in truth, most people are normal. However there are conditions that exist, where either over-sweating or under-sweating can be the result.

Why do some people sweat more than others?

Sweat rates will vary widely between people for a number of reasons. Generally the higher the metabolic rate, the higher the sweat amount, and this can vary between body areas too. For example, if you are working out in the gym and using more energy in your arms then legs, it has been found in many medical studies that the arms will sweat more than the legs. 

Some medications and illnesses can also cause sweating. Obviously infection can cause sweating as our core body temperature rises to fight the bacteria or virus. However less commonly known causes of sweating can be Hypoglycaemia (low blood sugar), some opioid pain killers, some thyroid synthetic hormones, and sometimes cancer. As I am sure many women know, menopause can also produce hot flushes, and associated sweating too.

As mentioned earlier, emotional stress can also cause sweating. It can be very distressing for people who suffer from anxiety or depression, as they will feel their core body temperature rise, and then sweat will bead. This can cause further anxiety.

Generally the fitter you are, the more you will sweat (damn it!). Over many years, there have been several studies that show that fitter people sweat sooner and more efficiently than less fit people. So sweating can just be a sign of your body functioning optimally too. There is also a relationship between the amount you sweat and the amount of oxygen that you breathe in. The fitter you are, and the more aerobic endurance you have, the higher the maximum oxygen uptake you will have. This is linked with sweating faster and in larger amounts. It does get confusing though, as the less fit you are, the harder your body has to work to undertake the physical exertion, leading to sweating too, The difference is that the fitter person will achieve a much greater exertion to produce sweat, whereas the unfit person produces sweat with less exertion. So in summary, when you are fit, you will less likely raise a swear doing daily activities because you don’t need to exert yourself as much as an unfit person. 

Is there an amount of sweat considered ‘normal’ or ‘abnormal’? How can a person tell where on the spectrum they are?

ruined makeup due to sweating

Sweat quantity is very difficult to measure, so most medical assessment is determined by the impact sweating has on your life. Excess sweating can be defined as:

  • sweating regularly from your face without any prior exertion
  • if you avoid social functions or other social activities due to fear of sweating
  • you primarily choose dark clothes to avoid people noticing sweat marks
  • sweating through the night, especially for those in their 20s and 30s, as this may be a sign of underlying medical conditions
  • if you avoid shaking hands with others due to sweaty palms
  • you sweat even when you are cold, or have not had any physical activity
  • you commonly have skin infections such as athlete’s foot or groin “jock itch”. Both of these conditions can be due to excess water on the skin, helping to assist bacterial and fungal growth.

Sometimes an iodine-starch test can be done. Essentially this is where iodine is wiped over your skin and then sprinkled with starch. There is a reaction between the two when you sweat, causing the iodine to show up as dark brown. This helps to give an indication of where the sweat glands are located, how many there are and the level of sweat that you experience.

Although there are several calculators for sweating available, I find that these are very difficult to use, and there are so many variables that they are of little use. I feel that the bottom line is, if you are worried about the amount of sweat your are producing, you should see your medical practitioner. This will help rule out and underlying medical cause to the sweating, and define whether you need treatment for sweating.

sweating through running

What are some common sweat myths that you hear touted as fact?

The most common misconception about sweating is that it smells. The smell does not come from the sweat itself, but from bacteria on the skin breaking down the fat excreted in the sweat from the apocrine glands. These are most common in the armpits, and also the scalp.

Similarly, most people think that sweat is yellow, which is why the armpits of our favourite white T-shirt becomes discoloured. Again, sweat is clear. It is the breakdown of the fat within sweat by bacteria that cause the yellowing effect.

Another myth that has been going around for years is that you sweat out weight. Sure losing water through sweat theoretically will cause your weight to fluctuate. This can be around 10kgs in someone who works in a hot physical environment. But this is not fat that is being lost, just water. And if this water is not replaced by water intake, a person can very quickly become dehydrated. Your body will crave water after sweating, and of course as soon as you replenish that water, your body weight will return right back to where you started.

A common belief is that sweating makes you breakout. But in order to have a breakout, you need to have dead skin that blocks the oil glands, and also acne producing bacteria in your skin. However it is important to wear sports clothing that allows the sweat to escape, so that you do not get infections on your skin due to sweat building up and keeping the skin hot and moist for long periods of time.

Finally another myth that is really common is that you will sweat out toxins. But in truth, sweat is water (about 99%), some salts or electrolytes,  and some fat or oils. Little else is lost in the process of sweating This is the reason hot steam saunas where so popular back in the 80’s. However the liver and kidneys are responsible for toxin release. 

If a person is concerned about how much sweat, are there ways of treating the condition? Be it fitness/diet, or cosmetic/dermal/medical procedures?

As mentioned earlier, if sweating is a concern to you or interfering with your daily life, the first place to start is talking to your medical practitioner to rule out an underlying medical condition. Once you have taken this step, there are a number of ways in which to control or reduce sweating.

antiperspirant versus deodorant

Reducing spicy or trigger foods in your diet will help reduce sweating. Also practicing meditation and reducing stress may also help to reduce sweating as your emotional wellbeing flourishes.

Becoming physically fitter is always a great option, as your body needs to work harder before it will raise a sweat. This means that day to day activities are less likely to produce sweat as you get fitter.

Antiperspirant are an easy and accessible way to control sweating. However if you have excessive sweating, you may require prescription strength antiperspirant.  These can have a great effect on some people, but can be very irritating to the skin in others. However this is a great place to start when considering treatment.

Nerve-blocker medications are another option. Again these can have both positive and negative effects in people. The medication works by blocking the ability of some nerves to communicate with the sweat glands. However the possible side effects include dry mouth and eyes, blurred vision and bladder problems, as the medication is not always highly selective for sweat glands.

Since sweating can be associated with anxiety, anti-depressants can be used to help reduce sweating too. 

The use of anti-wrinkle injections, can also be used to reduce sweating in localised areas. The iodine-starch test is usually performed first to identify the area and number of sweat glands, and then these are targetted with anti-wrinkle injections. This works by stopping the ability of minute muscles that excrete sweat being able to push sweat out onto the skin. The most common areas that this is undertaken is in the armpits. However more recently, micro-doses of the botulinum toxin can be used over the face and scalp too, to reduce sweating in more widespread areas without the usual associated frozen effect.  This micro-dosing can also help to reduce the size of pores on the face too.

Finally where all else fails, other options include surgery. The sweat glands can be removed, or nerves to them severed to stop sweating completely to localised areas of the body. However the side-effect of this can be excess sweating elsewhere, as the body tries to compensate. Plus surgery is not an option for everybody either.

This article was originally published in US Strong Magazine July 2019 and read it online HERE

Thanks for reading!

Written by Giulia D’Anna

BDSc (Melb), MRACDS, Honorary FIADFE (NY), Graduate Diploma Dermal Therapies (AACDS), Cert. Practice Man (UNE), Editor APJ (APAN) + | + 3 Belmore Road, Balwyn North, Victoria, Australia 3104 + | + Founder of iDental and Dermal Distinction

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