By Sarah Robson, RMT

July 17, 2012 • Massage Therapy

Most of us are uncomfortable about our sweat; we feel embarrassed if people see how much we sweat and try to decrease it by using antiperspirants. However, sweat is a natural, healthy process and we should be embracing our sweat! Throughout the ages there are many cultures that have promoted sweat through saunas and sweat lodges. The primary function of sweat is to help keep us cool in hot weather, but it also cleanses our skin and can remove certain chemicals from our bodies. In addition, we have increased sweating when we are nervous, emotional, and have nausea.

There are 3-4 million sweat glands in our skin and they are found everywhere in the body except for the lips, nail beds of the fingers and toes, parts of our reproductive organs, and the eardrums. There are 2 types of glands: Eccrine and Apocrine. Eccrine glands are the most widespread on the body, located everywhere, but we have the highest number in the palms and soles of the feet (these glands have a watery secretion). The Apocrine gland is found mainly in the axilla, pubic region, and the pigmented area around the nipples (this gland has a thicker secretion. Sweat is mainly water, but it also contains lactate, urea, and minerals (sodium, potassium, calcium, magnesium & trace elements). The mineral composition of sweat varies with the individual and depends on how they are acclimatized to heat, the nature of the stress source (i.e. sauna vs. exercise), duration of the sweating, and what concentration of those minerals are in the body to start with.

When our core temperature rises, our body needs to do something to release the heat: a signal is sent to increase sweating. The sweat exits out of the pores and onto the skin. Once on the skin the fluid evaporates. The energy required for evaporation comes from the heat of our bodies, so the evaporation leaves the skin cool. The blood in the vessels of the skin then cool down and return to the core of the body, counteracting the rising temperature of the core. If you are in a humid climate, evaporation is less effective and therefore, you don’t cool off as well. A person who lives in a cold climate may not feel like they sweat all that much. If they were to move to a warmer climate it may take a while to acclimatize to the new environment. Initially, they may feel they don’t sweat enough and the sweat they do produce has a high content of solutes (the solids found in sweat, like sodium). As the person becomes acclimatized, the amount of sweating increases and the amount of solute decreases. This is an excellent adaptive mechanism of our body. The biggest risk of sweating, “too much”, is of becoming dehydrated and/or having an electrolyte imbalance. Whether you are sweating through exercises or in a sauna, you need to be mindful of replacing the fluids lost. The more you train your body to sweat, less of the vital minerals will be lost and the re-hydration process will not be as complex. Here is a link to my previous article on hydration.

Our skin is the protective outer layer of our body. During the day, oils from our pores accumulate on the skin; dirt and environmental chemicals also get trapped on the skin surface. When we sweat, the fluid coming out of the pores helps to unclog them and wash away the dirt and chemicals trapped there. Sweating can also be a pathway for certain chemicals to be removed from the body itself. There are certain chemicals that have been proven to be released through the sweat in significant amounts. A lot of chemicals are filtered out of our bodies by our liver and kidneys (urine); but there are a few cases where the sweat is an important route a chemical is removed from the body, as the liver and kidneys do not seem to be effective pathways. In Dr. Stephen Genuis’s (University of Alberta) research he found that cadmium was not even detectable in 50% of the blood serum and urine tests, but was found in a significant amount in the sweat of those same participants. Through Dr. Genuis’s research, he deducted that sweat should be used as an additional way to measure the presence of certain chemicals in the body that do not show as clearly in blood and urine tests. He also concluded; “induced sweating may have a potential as a clinical intervention for elimination of some toxic elements.” Some of the substances shown to be excreted out of the skin during sauna therapy are morphine, methadone, amphetamines, chlorinated pesticides, herbicides, bisphenol A (BPA), toluene, cadmium, mercury, lead, and PCB’s.

There seems to be a big range in what is considered a ‘normal’ amount of sweating. It depends on the area of the world we live, how much we have trained our sweating mechanism, and what conditions the body is under at the moment. That being said, if there is a sudden change to your regular sweating amount, it may indicate an underlying pathology. A few causes of hyper-hydrosis (too much sweating) are hormonal imbalance, reaction to medications, infections, hyperthyroidism, and certain cancers. If you cannot sweat normally it is called anhidrosis. This can be a dangerous condition because your body can’t cool itself, leading to over-heating and possible heatstroke. Some causes of anhidrosis are genetic predisposition, skin trauma, medications, and certain diseases (i.e.: Diabetes, Parkinson’s, alcoholism, and some diseases which affect nerve function). It is important to consult your physician if you have changes in your sweating patterns.

Why are we so uncomfortable about our sweat? One reason is the perceived notion that sweat causes odour. The sweat itself does not smell. It is the bacteria that lives on our skin and feeds on the sweat that creates the smell. We often use an antiperspirant and deodorant to manage the sweat in our armpits. The antiperspirant’s active ingredient is an aluminum–based compound that works to swell the cells as water is drawn in with the aluminum ions. This swelling squeezes closed the sweat gland duct so the sweat can’t get out. In someone with over-active sweat glands this can be a blessing and regular use can even shrink the gland and reduce the sweat produced. In most “average sweating” adults, it is best to not prevent the sweat from occurring. If you wash regularly it will help with the odour, as it cleanses away the bacteria on the skin creating the odour. If the odour is an issue then there are many great deodorants which can help mask the smell.

We need to sweat! Some resources say we should sweat every day to have healthy skin and maximize the skin’s function as a detoxifying organ. It doesn’t matter how you do it; whether it is aerobic exercise, hard physical labour or frequent use of saunas. It just matters that you get your sweat on!

Sources and resources

• Principles of Human Anatomy 7th Es.;Gerard J. Tortora; Harper Collings College Publishers, 1995
• The Complete Natural Medicine Guide to Breast Cancer. Sat Dharam Kaur, ND. Robert Rose Inc. Toronto. 2003
• Stephen J. Genuis, Detlef Birkholz, Ilia Rodushkin, Sanjay Beesoon; Blood, Urine, and Sweat (BUS) Study: Monitoring and Elimination of Bioaccumulated Toxic Elements; Arch Environ Contam Toxixol, November 6, 2010