All about sweat, a mechanism that keeps us cool

• ROCÍO R. GARCIA-ABADILLO

  Madrid

Updated Sunday, August 14, 2022-06:55

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• Boticaria García These are seven ways to end sweat and some are forever

• Heat stroke This is how our body reacts to extreme temperatures

Few things have such a bad press as

.

Seeing someone whose drops fall off their face or with those typical circles in their armpits that in 2002, after the World Cup in Korea-Japan, were baptized as

in honor of the Red team coach, is an image that makes you feel uncomfortable.

Despite being something absolutely natural -and necessary-,

that reveal perspiration.

Perhaps it is because it can be a bit unsightly (even the phrases 'sweat like a pig' or 'sweat like a chicken' evoke an image that is not very suggestive) or because it shows that we are nervous or stressed in certain situations or because

, something that does not have to be this way: hygiene does not affect the amount of sweat nor does it condition its 'fragrance'.

Also because since the beginning of time with that divine punishment of "you will earn your bread with the sweat of your forehead" we associate it with

to achieve something:

... (curiously enough , however, that something 'sweats you' is that you don't care about anything).

Even fear in certain situations manifests itself as

running down our backs.

Leaving aside the fantasies of language, and whether we like it or not, the truth is that

.

"Sweating has several functions in our body. The first and main one is

. It has an emotional function (when we feel fear, stress, tension), an excretory function to eliminate the products of waste that is produced by the body's metabolism, and other more secondary functions", explains the specialist in Dermatology Nuria Rodríguez Garijo, from the University Clinic of Navarra (CUN).

Focusing on the main function, the average body temperature is 36-37 degrees, although it can vary depending on the time of day (it is lower in the morning or while we sleep) or throughout life (it rises in some phases of the menstrual cycle or in menopause).

(this summer with so many heat waves we are experiencing what it means to break a sweat).

Also due to excess weight or some foods, such as spicy foods.

This rise in temperature

, and this sends messages through the neurons of the sympathetic nervous system to the millions of sweat glands that we have so that they produce more sweat.

That sweat

.

Curiosities about sweat

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Figures around sweat

We have

of our body (with the exception of the lips, nipples and the outside of the genitals).

In general, we sweat an average of 700 milliliters per day (obviously there are those who sweat less and those who sweat more than that), but

when doing intense physical exercise.

Does not lose weight or eliminate toxins

Sweat eliminates water that obviously needs to be replenished (so as not to dehydrate us, especially in high temperatures), therefore it is not useful for losing weight.

So be

.

Being almost all water and mineral salts, the waste material is minimal, it does not eliminate toxins (the liver and kidneys are the organs that are in charge of doing it).

Who sweats more, men or women?

Dr. Ana Molina in her book 'Healthy skin, beautiful skin' points out that it has always been said that men sweat more than women, but in reality they have more sweat gland density than men.

The higher rate of sweating observed in men is due to "

, and not to sex 'per se'. What happens is that when these muscles work, they produce kinetic energy that is dissipated in the form of heat, and all that heat must be cooled", so the dermatologist concludes: "What we could say is that

".

Factors Affecting Odor

In addition to the microbiota (the bacteria on our skin), there are other factors that can affect body odour.

For starters

.

Also, for example, some

such as garlic, onion or asparagus can alter the composition of sweat.

Some

are excreted through sweat and can modify their smell (for example, penicillins or bromides), as well as certain

(they are usually rare diseases).

What is that temperature from which our cooling system is triggered?

Depends on the person.

"It is not mathematical, there is no temperature from which it is activated, unless it is known. It is when it interprets that your body is hot, that the outside temperature is high. But

, "says Paloma Borregón, dermatologist at the Spanish Academy of Dermatology and Venereology (AEDV).

Yes, it is a matter of genetics, luckily some may think.

The truth is that by excess or by default, in both cases there are drawbacks.

Thus,

in summers like the one we are experiencing, so these people should drink water even if they do not feel thirsty (which is not immediate).

Doing intense exercise you can lose from 1.5 to 3.5 liters of sweat per hour, so

(sodium, potassium, magnesium...) since it can be dangerous for our brain.

On the other hand,

and using again as an example this summer of infernal heat waves, "have

because this mechanism of cooling of the body is totally cancelled," says Dr. Rodríguez Garijo .

"People who sweat little are usually young children because they still have all this immature system, older patients and chronic patients. Then also in certain very specific genetic diseases the entire thermoregulation system is not developed," adds the specialist.

Hence, they have been warning all this summer that they are the most vulnerable groups -along with pregnant women, who have a higher basal temperature, among other factors- in the face of heat stroke.

Serena Williams breaks a sweat during a game held on Monday, August 8 at York University's Sobey's Stadium in Toronto, Canada.STEVE RUSSELLGETTY IMAGES

In any case, sweating a little is not considered a pathology, but sweating a lot can be.

This is

.

"It is much more frequent than people think.

and the causes have not been extensively studied because it causes shame or has been taboo, but it is generally caused by a

, which under certain circumstances and in certain people it is activated more than it should be under normal circumstances", points out María Rodríguez Pérez, specialist in Thoracic Surgery at the CUN.

"The sweat glands are more active than normal, they are activated without the need to have that increase in temperature. It is not that they need to eliminate sweat, but rather that

, summarizing a little the mechanism that would be more complicated," argues Borregón.

"What hyperhidrosis implies is that it

, many cannot carry out their work normally and it affects their social relations, since it greatly limits their activity," adds Rodríguez Pérez.

The most frequent are palmar and plantar hyperhidrosis.

We have different types of sweat glands depending on the location.

The

that we have, they are distributed throughout the skin surface, especially on the

(hence they are the most frequent hyperhidrosis), they are the ones that more contribute to sweating.

The

.

Hyperhidrosis can be primary, which also has a psychological component (for example, situations that can make one nervous and these people do not have normal sweating, but increased), and secondary, which can be related to tumors and other types of diseases, explains Rodríguez Pérez.

Treatments for hyperhidrosis

The first is usually treated, which is usually located in a specific area and affects patients more.

Treatments are usually staggered, going from less to more.

Thus, the first and perhaps obvious thing is

;

the use of

, as well as creams and pills, which act at the level of the receptors of the sweat glands;

or

, which is included in electrotherapy.

It consists of placing the hands in a container with water and passing a low-intensity continuous electrical current through the tissues.

"If you hold your hands for 10-15 minutes, it is also used in physiotherapy for muscle and joint inflammation, it does not have many adverse effects, but there is very little evidence for excessive sweating," says Rodríguez Pérez.

In addition,

due to the more complex innervation of the soles.

How to use deodorants and antiperspirants

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In 'Healthy skin, beautiful skin', the dermatologist Ana Molina draws up a list with the commandments for the correct use of these products.

1) Apply both to clean, well-dried skin.

2) Apply

.

3) Apply

.

4) Use antiperspirants

during times when you want to reduce sweating.

If we apply them alternately, it can affect the microbiota of the axillary area.

5) Use the recommended amount of product, without excess.

6) Do not apply them on eroded, irritated skin or immediately after waxing or shaving the area.

7) If there is a lot of hair in the area, the application will be more effective if the hair is trimmed.

8) If the deodorant is a

or stick, do not share it with other people.

9) Wait a while for the product to dry on the surface of the skin before getting dressed.

10) Renew them after a few hours and

.

Botulinum

, not only serves to prevent wrinkles, but also relaxes the sweat glands, making them sleep.

It is injected in the armpits, hands and feet and is quite effective, but

, and its duration is less and less because it is losing effectiveness.

"Imagine a communication system and we have to cut it off. You can cut it at the end of the system, between the neuron and the gland, by injecting Botox, or at the beginning of the system, in the nerve, through

. Without nervous stimulation the sweat gland cannot function", analyzes Dr. Borregón.

"In this

that runs inside the chest parallel to the spine, at different levels of the ribs, depending on whether it is the hands, feet or face. The higher it is done, the more risk there is We make very small incisions, five millimeters in. Many people are afraid of surgery, but we are talking about an

that is done on the day," Rodríguez Pérez emphasizes.

Is the human being the only one who sweats?

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Any animal with sweat glands has the ability to sweat, almost all mammals, but some sweat from different places and not all over the body like

.

Dogs sweat through their paw pads, but lose most of their heat through panting.

Other good sweaters like people and some apes are the

.

Contrary to what is thought about 'sweating like a pig', pigs barely sweat (only in the interdigital area, on the snout and foreskin).

The expression comes from a mistranslation of the English 'sweat like a pig', but refers to 'pig iron' (product resulting from melting iron in a blast furnace: pig iron), not the animal ('pig').

Hippos don't sweat blood.

A few centuries ago, the first Europeans who went to Africa thought that hippos sweated blood, although it is not blood nor is it strictly sweat, but we could call it that.

The thin skin of these animals dries and burns easily (that is why they are always in the water or take mud baths), which is why they

.

The magazine 'Nature' published two decades ago the analysis carried out by a Japanese team: it contains hyposudoric acid (red in color) and norhiposudoric acid (orange in color) that

(they repel water) .

).

In addition, the hyposudoric is

, and prevents bacteria from proliferating in the wounds that these animals make when fighting.

The CUN Thoracic Surgery specialist emphasizes that it is very important to carefully select patients "who have tried other treatments and that hyperhidrosis effectively conditions their lives."

"When they enter the consultation it is very

, literally. They leave them leaning on the table and leave drops of sweat or

. I had the case of an electrician who was electrocuted, he couldn't do his job because of the moisture on his hands. Also, these are people whose hands are excessively cold."

Also, adds the doctor, "that they accept the possible secondary effects that may occur, such as

": what is not sweated through the hands or armpits, in the end

, the areas where this compensatory hyper-sweating occurs most after surgery.

"There is nothing that helps us to predict which patients are going to present it or not, but generally the satisfaction rates after surgery are very high, it is people whose lives change completely," says the specialist.

In this regard, the director of the Department of Thoracic Surgery of the CUN, Miguel Mesa, comments: "One of the main elements of the avant-garde in the new surgical technique is the possibility of this minimally invasive surgery, instead of cutting,

Faced with this compensatory hyperhidrosis that may exist and if it is severe it can make the patient regret the surgery,

.

There is not very solid evidence because in a few cases it has been necessary to remove a clip, but in my personal experience and that of many other teams that are working with a high volume of patients, this surgery with clipping allows reversibility".

Mesa highlights that the benefit of this surgery is evaluated based on the degree of satisfaction.

"

. Although compensatory sweating generally reaches up to 60% - serious sweating only 3-5% -, the patient is happy because the change in life It is radical, since it limits many people a lot".

Another possible complication is in the case of excessive sweating on the face or excessive facial flushing.

"The sympathetic chain also innervates the autonomic muscles of the eye and produces the secretion that keeps it hydrated, so if the sympathetic chain is cut very high up and the ganglion from which the endings that can go to the eye come out is affected, it produces the so-called

In some series the risk of Horner syndrome goes up to 20%, if they are very high sections, but they are old series For hyperhidrosis in the hands and armpits, which are more modern series, the risk is less than 1%", indicates Rodríguez Pérez.

What does sweat smell like?

Although it is a controversial issue, the truth is that sweat does not smell like anything.

with metabolic waste, minerals like sodium, chlorine, potassium, or urea (the stuff in urine), but it's basically water with sodium chloride (salt).

that some have more than others

, or what is the same:

that are distributed differently. In the armpits we have different bacteria than we have on the face or in other places, that's why the smell of some areas is different from others," says the Borregon Dr.

Dermatologist Ana Molina always says with great humor that "these bacteria eat, fart and poop. They feed on products present in our sweat and generate odorous molecules, such as ammonia and short-chain fatty acids."

In short:

(the ones that each one has).

"That bad smell or bromhidrosis can also be due to some drugs, for example for Parkinson's. Some foods can also increase it and some pathologies, for example,

and this is It is due to a poor absorption of different substances in the diet that are metabolized in an altered way in the gastrointestinal tract and produce this bad smell. By eliminating certain compounds from the diet, these patients improve", indicates the CUN dermatologist Nuria Rodríguez Garijo.

These bacteria do not always remain the same, they also

.

The flora can be altered, for example, by taking antibiotics, which could alter the smell "and genetics also change with the races,

to us, sometimes very strong,

. Anyway, that's very subjective and it's not smelling bad, nor does it depend on how much you sweat," says Borregón.

The topic of skin microbiota is very fashionable right now, it is in full development and it has been seen that the load of microorganisms that we have on our skin (which can be altered with changes in diet, hygienic habits and other parameters ) influences dermatological pathologies, other pathologies of our body and also, of course, hyperhidrosis and bromhidrosis", concludes Rodríguez Garijo.

What sweat says about health

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As explained by the dermatologist Rodríguez Garijo, transepidermal water loss is used to measure some pathologies that have greater or lesser transepidermal water loss.

Until recently, sweat was used only for

(sufferers have higher amounts of sodium and chloride in their sweat) and

testing (opiates, amphetamines, and , cocaine or cannabinoids, so it is very useful to evaluate doping; also to know if ethanol has been ingested, that is, alcohol).

There are already quite a few

in the scientific literature .

For example, in

(samples are taken from the sole of the foot with a patch that changes color when moistened).

In invasive breast cancer cells and in brain neurons, a peptide called dermcidin appears, which is also found in sweat, and another disease prognostic marker is prolactin-induced protein, which is expressed in sweat glands and is overexpressed in

prostate

In sweating, toxic metals are also excreted from the body, comparable to urine, so it could be used as an alternative route in some

.

Some studies analyze biomarkers in sweat that are also related to

.

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