Sweating - what it is and how it affects people

Sweating, also known as perspiring or transpiring, is a completely natural process: It is a very important physiological response to warm temperatures or physical activity. In humans, evaporative heat loss from eccrine sweat is critical for thermoregulation during exercise and/or exposure to hot environmental conditions, particularly when environmental temperature is greater than skin temperature. Sweating can also be triggered by emotional stress.

SIGNS & SYMPTOMS

What is sweating?

When sweat is produced, this usually means the body is doing its job of keeping you cool. In most cases, a person sweats in response to warm temperatures, exercise or certain emotional situations. As sweat evaporates from the skin, it absorbs heat energy from the body and thus cools us down.

Mostly, moisture or wetness will appear on armpits, hands or the face. It may be unpleasant when signs of sweating begin to show. Especially in armpits, sweating may cause wet patches on clothing and sweat metabolising bacteria may cause unpleasant odour.

The amount of sweat a body produces varies considerably from one person to another. On average, it tends to be between 0.1l and 1l a day.
When sweating is excessive (perspiring profusely and in the absence of any obvious reason), this condition is called Hyperhidrosis.

Woman with towel around neck
Sweat is a natural way of regulating body heat.
CAUSES & TRIGGERS

MAJOR CAUSES & TRIGGERS FOR SWEATING

Our skin contains diverse types of glands and it is some of these that produce sweat. When those sweat glands receive signals from the brain, they release perspiration through our pores.

As soon as your brain detects that your body temperature has risen above 37°C/98,6°F, it will send signals to your sweat glands to produce and release a liquid: This liquid – sweat – cools the surface of your skin by evaporation. When we are hot, active, nervous or stressed, sweat glands are stimulated to produce more sweat. 

Every person has between 25,000 and 50,000 sweat glands in their armpits alone. 

This is actually only a small percentage of the total amount of sweat glands (approximately 1.6-4 million sweat glands in total, all over our bodies). These are most dense under our arms, on the palms of our hands and on the soles of our feet. As the sweat is more likely to be “trapped” under the arms – also due to clothing – where it cannot escape, this is where it tends to become most noticeable. Fresh sweat itself does not smell; it is odourless. It can lead to wet patches and thus make sweating visible to others. Only when bacteria go to feed on the proteins and lipids (contained in the sweat) unpleasant and unwanted body odour will occur.

Face close-up with sweat
Eccrine glands produce a large amount of “wet sweat”.
Woman wearing lilac shirt with sweat stains under arms
Choose either light or very dark clothing that will conceal the signs of sweating.

Two types of sweat

There are two types of sweat glands on our bodies – eccrine and apocrine.

Eccrine glands are found all over our body and control temperature. Eccrine sweat is usually odourless and colourless. It contains 99% water and various salts and amino acids. 

Apocrine glands are concentrated in certain areas only, such as the armpits, genital area or scalp (areas with hair follicles) and can be triggered by stress.

Apocrine glands, which are activated during puberty, produce sweat that is high in proteins and lipids. The amount of apocrine sweat is much lower than the amount of eccrine sweat. Its composition though attracts bacteria, which are responsible for the formation of unpleasant body odour. Further apocrine sweat plays a role in the formation of yellow stains.

Illustration of sweat glands.
Sweat glands release perspiration through our pores.

Consequently there are two different types of sweat:

  • During thermal sweating induced by elevated temperatures or physical activity only eccrine sweat glands are active.
  • During emotional stressful situations both eccrine and apocrine glands are active: Eccrine glands produce a large amount of “wet sweat”. Additionally apocrine glands produce a small amount of sweat that is rich in lipids and proteins and thus is responsible for the formation of unpleasant body odour when metabolised by bacteria. 


CONTRIBUTING FACTORS

Sweating - NOT ONLY A PREDISPOSITION

Genetic factors and predispositions are mainly responsible for the amount we sweat. They determine, for example, the amount of sweat glands in our bodies and where they are located.

There are, however, some other factors that can play a role in sweat production. 

  • Physical activity
  • Climate
  • Stress or nervousness
  • Hormonal changes such as puberty, pregnancy or menopause
  • Some metabolic diseases (diabetes mellitus, impaired thyroid gland function)

Other factors, like drugs, alcohol, nicotine and coffee, as well as spicy or very hot food, can also affect the amount we sweat. 


Woman looking stressed
Stress or nervousness can trigger sweat production.
Solutions

DEALING WITH SWEATING

Although there is no “cure” for sweating, which is a completely natural bodily function, armpit sweat and its unpleasant effects such as body odour can be reduced.

Cosmetically, there are two ways of dealing with sweat under the arms:

  1. Deodorants
  2. Anti-perspirants (also called Anti-transpirants)

Woman using Eucerin 48 h Anti-Perspirant Roll-on
Eucerin Anti-Perspirant helps to prevent body odour and its development.

How deodorants work

Deodorants can effectively prevent body odour and its development. To accomplish this, various action principles and combinations of ingredients are used:

Deodorants contain substances that will either absorb the odour-producing bacteria (called bacteriostasis) or will slow down their reproduction: Antiseptics reduce the amount of bacteria and the creation of an acidic pH on the surface of the skin slows down the growth of bacteria. Through these effective substances deodorants reduce the formation of body odour.

However, deodorants do not have a significant effect on the amount of sweat produced. Many deodorants further contain fragrances to mask the unpleasant smells. Apart from other irritants such as alcohol, preservatives or colorants, the fragrances are one of the reasons why some people may be allergic to deodorants.

Woman touching her armpit
With sensitive skin you should use a deodorant that suits your skin type.

All Eucerin deodorants are proven to be especially skin-friendly in clinical studies, even in cases of deodorant intolerance, eczema or Atopic Dermatitis, proving 24 hours of protection against odour.

How Anti-perspirants (= Anti-transpirants) work

 All Anti-perspirants (also known as Anti-transpirants) contain aluminium salts like Aluminium Chlorohydrate (ACH) or Aluminium Chloride (AC). These act on the eccrine and apocrine sweat glands by partially and reversibly clogging the duct of the sweat gland, thus reducing the amount of sweat that is produced. Due to the reduced formation of sweat, there is less dampness and noticeably less odour. Aluminium Chloride acts most effectively: As the AC complexes are smaller and have a lower pH value than the ACH complexes they can penetrate even deeper into the sweat ducts, keeping them closed for longer. 

If even highly effective Anti-perspirants do not protect you enough from sweating, you may well suffer from Hyperhidrosis.

If you have sensitive or previously damaged skin, allergies or eczema – or you suffer from excessive or heavy sweating – it is especially important that you use a deodorant or Anti-perspirant that suits your skin type.


Woman using Eucerin 72 h Anti-Perspirant Intensive Pump-Spray
Deodorants contain substances that will either absorb the odour-producing bacteria (called bacteriostasis) or will slow down their reproduction.
Woman shaving her armpit
Shaving can cause skin irritations.

It is important that you find a deodorant or Anti-perspirant to match your needs and skin type.