Pros and cons of sauna use: The truth exposed

Heather Campbell
 min read

Pros and cons of sauna use are often up for debate, so we thought it an interesting subject to tackle.

Pros and cons of sauna use: The truth exposedIf the advertising for saunas is to be believed, they have numerous health benefits and hardly any drawbacks. But are all these claims true?

As a general rule, saunas are enjoyable and relaxing. It is reported that there are a number of health benefits, while at the same time some view saunas as a potential health risk. As always, common sense is key, but it’s best to know the facts before using one.

Most people probably use the sauna for its relaxing and soothing effect, to enjoy the warmth in the winter, to walk around naked, because their skin feels clean and smooth after a sauna session, because they enjoy spending time with their bodies, etc.

There are also quite a few misconceptions about the potential dangers of a sauna for pregnant women, heart patients, diabetics, children, etc.

If the advertisements are to be believed, the sauna is not only fun and enjoyable, but also offers all kinds of health benefits. But, unfortunately, these claims do not always turn out to be true.

Read on to see what’s true and what’s not, and get a true picture of pros and cons of sauna use.

Pros and cons of sauna use: Introduction

There are two types of sauna:

  • The classic (Finnish) sauna
  • The infrared sauna

Classic Finnish sauna

In the classic Finnish sauna, the air is heated by a heat source.

A Finnish sauna’s operation relies on the interaction of hot, dry air with temperatures between 122 and 212 degrees Fahrenheit and a relative humidity of 15 to 30% and cold water.

Infrared sauna

The operation of an infrared sauna is based on infrared heat generated by electric emitters.

The hallmark of infrared heat is that it transfers heat to the skin without hot air.

An Infrared sauna is not actually a sauna but a radiant heat cabin.

The double walls of an infrared cabin will also increase the ambient temperature to between 104 and 140 degrees Fahrenheit.

What happens in the classic sauna?

The sauna has several physiological effects on the body, and we need to understand them well in order to see what the pros and cons are of sauna use.

Effect of a sauna on hormonal changes

A sauna session has an impact on our hormones.

The Hypothalamic-Pituitary-Arenal hormonal axis is activated and this results in the release of several so-called stress hormones.

For example, there is increased production of norepinephrine, prolactin, β-endorphin and growth hormone.

The production of cortisol, adrenaline, adrenocorticotropic hormone or corticotropin and testosterone (the male sex hormone) remains virtually unchanged.

Moisture loss due to a sauna visit

The moisture loss after a sauna session is approximately 0.13 to 0.26 liquid gallons.

Sweat contains less salt and potassium in its composition than blood composition, so there is a slight increase in salt and potassium levels in the blood.

The concentration of hemoglobin (the red dye in red blood cells) rises slightly. Hemoglobin is needed to transport oxygen from the lungs to the organs and tissues.

The fluid loss also activates the renin-angiotensin-aldosterone hormonal system.

When this hormonal system is activated, blood pressure rises, blood vessels in the kidney contract, and both salt and fluid are retained.

All this leads to a reduced feeling of pain, increased alertness and possibly slight euphoria.

Influence of sauna on heart function

The human body has a built-in thermostat that keeps the body temperature at about 97.5 degrees Fahrenheit.

In the sauna, the skin temperature heats faster than the body’s temperature: from about 90 degrees to about 108 degrees Fahrenheit (after 20 minutes), while the body temperature rises by a maximum of 34 to 36 degrees Fahrenheit.

Among other things, this triggers sweat production, which lowers skin temperature to slow the temperature rise.

The drier the air around the body is, the faster sweat evaporates and the faster you cool down.

At the same time, the blood vessels in the skin dilate, increasing the blood supply to the skin and removing warm blood and replacing it with colder blood.

This in turn raises the internal temperature.

Whereas normally only 5 to 10% of the blood flows through the skin, this can rise to 45 to 65% in the sauna.

The heart begins to pump faster and heart performance increases to maintain this mechanism.

The heart rate in the sauna can be twice as high as the resting heart rate, while the cardiac output (the amount of blood the heart pumps per minute) can be two to three times higher.

This roughly corresponds to an increase in heart performance during a brisk walk.

The effects on blood pressure are minimal because diastolic blood pressure drops slightly while systolic blood pressure remains almost constant.

In addition to the heat, the cooling phase also strains heart function, depending on the type of cooling.

When immersed in ice water, skin temperature drops very quickly from about 104 to 91 degrees Fahrenheit, while body temperature drops very quickly by 34 to 36 degrees Fahrenheit to return to normal temperature.

Among other things, this leads to a rapid increase in blood pressure.

Health claims of the classic sauna

Prostate hypertrophy

Claims:

The sauna would help against prostatic hypertrophy.

Findings:

There is no evidence for this in the scientific literature, so we can’t define pros and cons in sauna use in such a situation.

Immune system

Claims:

  • Cold prevention. Those who go to the sauna regularly suffer less from colds and are more resistant to temperature fluctuations and even the flu.
  • Heat exposure activates and strengthens the immune system by increasing white blood cells and antibodies.

Findings in practice:

  • A scientific study confirms that people who go to the sauna regularly (twice a week for six months) catch up to 30% fewer colds than people who do not go to the sauna. There is no effect on the severity or duration of the colds themselves.
  • Little research has been done on the effects of a sauna visit on the immune system.

Slimming with the help of sauna sessions

Claims:

  • A sauna session burns about 290 kilocalories, comparable to an hour of leisurely walking.
  • Sauna helps to lose weight.

Effects of sauna in practice:

If you weigh less after the sauna than before, it is only about water loss that is fully compensated during the first hours after the sauna. The average moisture loss during a sauna session hovers around 0.13 liquid gallons.

The reference to the energy consumed to sweat in the sauna is partly misleading.

In fact, even at rest, our bodies consume energy for heart functioning, breathing, urine production, etc. (the so-called basal metabolism). The amount depends on gender, age and weight.

In addition, it should be borne in mind that the energy consumed during exercise is primarily provided by the carbohydrates present in the body (in the form of glycogen).

Only a limited amount of fat is burned in energy production, which depends on the exercise’s duration and intensity.

Conclusion: If fat is burned by the sauna at all, it is all very limited.

Fertility effects of sauna visits

Claim:

Hot baths and saunas are harmful to male fertility because heat inhibits sperm production.

The testes hang in a bag outside the body. It keeps them cooler (91 to 93 degrees Fahrenheit). This is necessary for proper and quality sperm production.

Scientific findings:

Research effectively indicates reduced sperm motility during and immediately after a sauna visit but this is a temporary phenomenon.

There is no evidence of a negative impact on long-term fertility.

Skin and sauna

Claims:

  • Sauna reduces cellulite because it is a gel-like substance of water, fat, and waste products located just under the skin. The removal of this fat gives you tighter skin in these areas.
  • Sauna improves various skin diseases such as psoriasis, eczema, acne, etc.
  • A better blood flow ensures that your skin is cleansed from the inside out. All impurities are flushed out, as it were, and dead, cornified skin cells become softened and loosened.
  • The sauna improves and strengthens the elasticity of the skin structure. The aging process of the skin is slowed down for a while.
  • A sauna session avoids rough skin and makes your skin soft and smooth.
  • The skin renews itself more quickly as flakes of skin are loosened. Thus, the skin becomes softer and more supple.

Findings in practice:

  • On the concrete effects of a sauna visit on human skin, hardly any research exists. Most likely, it has a (slight) drying and cleansing effect.
  • Psoriasis: Scientific research shows that sauna has no effect whatsoever in most psoriasis patients. And in +/- 10%, a sauna session leads to a worsening of symptoms.
  • Rosacea (rosacea): Usually, sauna aggravates the symptoms
  • Eczema: Sauna worsens symptoms
  • Atopic dermatitis: sauna exacerbates symptoms and can even lead to an acute flare of urticaria (itching). Sauna is not recommended for people with chronic nettle fever (urticaria).
  • Acne: no known scientific research
  • Cellulite: no known scientific research
  • Effect of sauna on the aging process of the skin: no scientific research known

Breathing and respiratory diseases

Claims:

  • Chronic bronchitis: A regular sauna visit is very relieving for people who suffer from chronic bronchitis.
  • Asthma: Regular sauna visits reduce the number of asthma attacks, breathing difficulties become less severe, and vital capacity (the maximum volume of air, which passes through the mouth with a full inhalation or exhalation) increases.
  • Better circulation in the respiratory tract thanks to sauna
  • Mucus secretion in the respiratory tract is increased

Effects in practice:

  • Sauna use is safe for COPD patients and those with chronic bronchitis. There would be a slight improvement in lung function but it is very short-lived.
  • The same is true for asthmatics. There is no evidence that sauna use is harmful to asthmatics. Still, there is also no evidence that it would have a beneficial effect.
  • Sauna leads to a slight but very temporary improvement in lung function that includes increasing vital capacity (the maximum volume of air, which passes through the mouth during a full inhalation or exhalation).
  • Sauna use is strongly discouraged during acute respiratory infections.

Removal of toxins

Claims:

Sweating in the sauna removes toxic waste and fat-soluble substances (such as heavy metals) from our bodies to the maximum extent possible.

Practice:

There is no scientific evidence for a purifying effect of a sauna visit.

Side note: Numerous drug rehab clinics make saunas available to accelerate the removal of waste products and metabolites of drugs (heroin, alcohol, benzodiazepines…) from the body. However, there is no scientific evidence about the effects of this method.

Effects of sauna on digestion

Claims:

Regular visits to the sauna support regular bowel function and reduce the tendency for the stomach and intestines to cramp up.

Findings in practice:

There is no evidence for these claims in the scientific literature. There is some evidence that regular sauna use stimulates the appetite.

Muscle and joint disorders/pain

Claims:

  • Sauna has an analgesic (pain-relieving) effect
  • A visit to the sauna reduces gout symptoms
  • Sauna has a beneficial effect on rheumatic complaints. This is especially true of osteoarthritis, where there is pain and restriction of movement in the back and joints and where we feel tense and aching muscles.
  • Sauna accelerates recovery from muscle injuries by improving blood flow.

Effects in practice:

  • Studies in patients with (chronic) pain yield conflicting results. The sauna is likely a useful adjunct to other pain treatments but it is still unclear for which types of pain.
  • Regarding the impact of a sauna visit on gout, there is no evidence of a positive impact of a sauna session on gout symptoms. On the contrary, a sauna visit could more likely lead to worsening the symptoms.
  • Rheumatoid arthritis and fibromyalgia: Research in patients with rheumatoid arthritis and fibromyalgia shows that sauna often has a positive effect (less pain, less stiffness and more mobility) in the short term. This effect is more pronounced in men than in women. But half a day later, more than half of the patients found that the pain had become worse than before. Conclusion: A sauna session is not recommended for patients with rheumatoid arthritis during an acute flare-up.
  • Did you know: Sauna, in combination with appropriate exercise therapy, has a beneficial effect (on pain, mobility and the duration of morning stiffness) in patients with Bechterew’s disease.
  • No evidence exists for faster recovery of muscle injuries from sauna sessions. A sauna visit also has no meaningful impact on muscle stiffness and muscle soreness resulting from physical exertion.

Possible health risks of classic sauna

Heart patients and sauna use: Risks

Sauna use is safe for heart and hypertension patients whose disease has been stabilized or controlled (medicinally).

Still, heart patients do best to discuss with their doctor about the possible pros and cons of sauna use.

A sauna visit is highly inadvisable for heart patients with the following conditions:

  • Severe aortic stenosis
  • Unstable angina (heart spasm)
  • Severe orthostatic hypotension (low blood pressure)
  • Severe, uncontrolled hypertension
  • Recent heart or vascular problems (in the last few weeks or months), such as a heart attack

Some additional findings on sauna use by cardiac patients

  • Several studies indicate a possible beneficial effect of sauna on cardiac function and exercise capacity in patients with congestive heart failure or heart failure. This is a heart condition in which the heart can no longer pump sufficient blood through the body (especially with increased physical exertion). As a result, tissues and organs do not receive enough oxygen. Possible symptoms include shortness of breath and chest tightness (dyspnea) on exertion, rapid fatigue, and cardiac arrhythmia (arrhythmia). Left-sided heart failure causes fluid congestion in the lungs (pulmonary edema). Right-sided heart failure causes congestion of fluid under the skin, especially around the ankles (peripheral edema).
  • Sauna may have a regulatory effect on blood pressure. Under the influence of the heat in the sauna, the (diastolic) blood pressure drops slightly. The higher the temperature, the more it will drop. When cooling down, the opposite happens with the result that blood pressure rises.
  • There is some evidence that regular sauna visits may have a beneficial effect on blood cholesterol levels in people with elevated cholesterol levels.
  • There is no evidence that sauna use in people after a heart attack increases the risk of blood clots, bleeding, or arrhythmias.

Tips for heart patients

  • Leave the sauna room immediately if you do not feel well.
  • Do not take blood pressure-lowering medications before the sauna session and remove transdermal nitroglycerin patches before you begin the sauna session.
  • Start the sauna with a warm foot bath and dry the feet carefully.
  • When cooling, it is best to start gradually, from the bottom up. You should work toward the heart to cool the body after the sauna visit. Coldwater baths are not recommended for heart patients (because of the sharp increase in blood pressure).
  • After cooling down, take about 15 minutes to rest (there is often a soothing relaxation room where a relaxing tune plays).
  • If you have a choice of saunas, it is best to choose one with a temperature you can tolerate well (140 rather than 212 degrees Fahrenheit) and never for too long (about ten minutes at most, don’t overdo it).
  • You can sit up straight for the last two minutes to help your circulation so you don’t get dizzy when standing up.
  • Take a moment to catch your breath before starting the cooldown. If necessary, go for a walk outdoors.
  • Keep calm and relaxed in the sauna, enjoy the moment and put all worries aside for a while.
  • Attention: Avoid drinking alcohol before or during the sauna session.
  • Drink copious amounts of water during and after the sauna visit.
  • Do not go to the sauna immediately after physical exertion. This can lead to a drop in blood pressure resulting in fainting.

Varicose veins and/or hemorrhoids

Incipient varicose veins are not an obstacle to a sauna visit. Tip: Try to raise your legs (for example, lie flat on your back instead of sitting).

However, if you suffer from it to such an extent that your doctor forbids you to sit in the sun with your legs, for example, you would do well not to go to the sauna.

The same goes for hemorrhoids (also a form of varicose veins). If you are so badly affected that the slightest bleeding can occur, it is also better not to go to the sauna.

Diabetes

Diabetics should check with their doctor beforehand to ensure that the sauna poses no risks due to the possible unwanted effects of heat on blood sugar levels.

First, sweating can lead to a sharp drop in blood sugar levels.

In addition, the sauna’s heat leads to increased absorption of insulin. This can also cause blood sugar levels to drop significantly.

Therefore, it is recommended that at least two hours have elapsed since the last insulin delivery and the sauna visit.

In addition, it is recommended that you take some quick sugars with you to the sauna to solve any problems.

Conversely, the increased release of various hormones in the sauna can increase blood sugar levels.

Diabetics using a subcutaneous insulin pump should take extra care. The heat in the sauna can cause changes in the insulin that cause it to stop working. Therefore, it is recommended not to take the pump into the sauna.

Tips for diabetic patients

Diabetics should observe the following sauna tips to minimize health risks, so if this applies to you, read carefully to understand your own particular set of pros and cons for sauna use:

  • Do not consume alcohol before or during the sauna
  • Spend a short time in a hot sauna rather than a long time in a lukewarm sauna
  • No insulin injections just before the sauna session
  • After each session, cool down well (first in the fresh air, then cold water, starting with feet and arms, then upper body). Try to keep your feet thoroughly dry.
  • You must dry yourself thoroughly after the shower before the sauna session (feet must be dry)
  • Insulin pump not to take into the sauna is the message
  • Before the sauna session, you should test your blood sugar levels. Optionally, you can also test blood sugar levels after each session and after the entire sauna session. This is especially true for diabetics going to the sauna for the first time (or not regularly).
  • Enjoy up to three 8- to 12-minute sauna sessions and implement 15 to 30 minutes of rest between each session.
  • Do not go to the sauna on a completely sober stomach (but not on a full one either).
  • Stock up on quick sugars so you can make quick adjustments if needed.

Pregnancy and sauna visits

It’s important to ask your gynae about the pros and cons of sauna use.

Often, sauna visits are not recommended for pregnant women and especially during the first 14 weeks of pregnancy.

During this period, the sensitivity of the developing fetus to external influences is strongest. For example, high temperatures would increase the risk of miscarriage and cardiac or neurological abnormalities (such as spina bifida) in the fetus.

However, this claim is based on limited experimental research in animals. Several epidemiological and clinical studies in humans could not demonstrate an increased risk of miscarriage or congenital malformations.

In a normal pregnancy, a sauna does not appear to negatively impact either mother or child, so there is no reason to advise against sauna for pregnant women.

Only for pregnant women at increased risk of pre-eclampsia could heat exposure lead to complications and should sauna use be discouraged.

At the end of the pregnancy (the last 6 weeks), some caution is advised regarding taking a dip or bath because there may already be some dilation and the risk of infections could increase.

Tip: For more do’s and don’ts related to sauna use, have a look at our other article What is proper sauna etiquette? Do’s & don’ts & best tips

Children and sauna

Children’s temperature control is not yet fully established. In addition, they have proportionally more skin surface area than body mass compared to adults.

  • A sauna is usually not recommended for very younger children (2 years or less). There are, however, studies from Finland (where a lot of children under 2 years of age take weekly saunas) that show no problems for the smallest among us. This is provided that the temperature is not too high (less than 158 degrees Fahrenheit) and the duration is short (maximum 3 to 5 minutes per session).
  • From the age of 4 to 5, there is no problem at all. However, the child must always be accompanied by an adult.

Elderly people and pros and cons of sauna use

Those used to going to a sauna regularly do not need to stop this habit after having done it all their life, even past 60 years old.

However, a first sauna visit over 60 is not recommended.

Are you already a year older and does the sauna appeal to you? But have you never done so before? If so, talk to your doctor about it first.

In what situations is the sauna not recommended?

In the following circumstances, a sauna visit is not recommended (or at least requires the prior advice of a physician):

  • Severe varicose veins (or hemorrhoids)
  • Open wounds
  • Severe, uncontrolled hypertension
  • Acute flare-up of rheumatoid arthritis
  • Pregnant women at increased risk of pre-eclampsia
  • Recent heart or vascular problems
  • Severe orthostatic hypotension (low blood pressure)
  • Unstable angina (heart spasm)
  • Acute infections
  • Some skin conditions (such as chronic nettle fever, urticaria)
  • Severe aortic stenosis
  • Poorly regulated diabetes
  • Fever

Medicines and sauna

Do you take certain medications and want to go to the sauna? Here are some tips:

  • Lithium: Drink plenty of water so that dehydration will certainly not occur during your sauna visit.
  • Transdermal nitroglycerin: Because higher doses enter the blood due to the increased blood flow through the skin, removing the patches in the sauna is recommended. The same applies to nicotine patches (remove them if you are going to visit the sauna).
  • Insulin: see diabetes subtitle for more information.
  • Medicines for hypertension: It is not recommended to take blood pressure-lowering drugs before visiting a sauna because it may cause the blood pressure to drop too sharply.

Tips for safe sauna use

  • Do not go into the sauna just before or just after strenuous exercise.
  • Do not drink alcohol before or during the sauna session. In fact, alcohol can interfere with the heat regulation system and lead to overheating. The same is true of some drugs that affect sweating or blood pressure.
  • Stay in the sauna for a maximum of 15 to 20 minutes per session.
  • Drink two to three glasses of water after each sauna session.
  • Leave the sauna immediately if you feel unwell.

Tip: For more tips and insights on how saunas work and how to use them, read our other post How do saunas work & how to use a sauna? Insights & tips

Sauna and legionella

If proper precautions are taken, saunas pose a negligible risk.

Legionella is caused by the legionella bacteria (Legionella pneumophila). Legionella bacteria reside in tap water and can develop in stagnant water that has a temperature between 68 and 131 degrees Fahrenheit.

There are strict measures for saunas, swimming pools, and the like to prevent the development of Legionella bacteria.

The water temperature must always be below 77 degrees Fahrenheit for cold water supplies. The installation must contain only pipe sections in which flow is possible.

For hot water supplies, the temperature of the water must always be at least 131 degrees Fahrenheit. The production of hot water must be done so that there are no areas in the hot water production unit that are not raised to 140 degrees Fahrenheit at least once a day.

Showers pose an increased risk if the water temperature in the hot water system, i.e. before mixing with cold water, is below 140 degrees Fahrenheit. There are strict rules and controls for this as well.

Pros and cons of sauna use: Conclusion

With such an overload of information, it’s easy to think that all your health and beauty problems are resolved by going to a sauna, and in fact, it can be a greatly beneficial experience.

On the other hand, it’s not for all, and this article explaining the pros and cons of sauna use should put your mind at rest so as to know what’s what in sauna use. Enjoy!

About Heather Campbell

As a dietitian, my field of specialization is science-based nutritional advice but more importantly, it is my goal to share capturing and inspiring stories, examples and solutions which can help plus-size individuals overcome their specific difficulties. Read More