Why do we perspire?

Definition of perspiration

  • Perspiring is a normal physiological phenomenon and helps to control the body's temperature, maintaining it at constant temperature of approximately 37°C.
  • Perspiration allows the body to cool.
  • Sweating helps the body regulate its temperature. Sweat is produced by the sudoriferous glands.
  • During physical activity or hot temperatures the body's temperature increases. The body reacts in order to lower its temperature by producing sweat, which will evaporate after.

Sudoriferous glands

  • The body contains from 2 to 4 million sudoriferous glands, which are distributed over the entire skin surface.
  • The sudoriferous glands allow the body to evacuate the excess of heat by producing sweat: the evaporation of sweat gets rid of body heat.
  • Their numbers vary from one part of the body to another.

Localisation of the sudoriferous glands

  • The majority of sudoriferous glands are on the soles of the feet, the palms of the hands, the groin and the armpits.
  • They are ten times more present at the level of the feet and the hands than in the back.

Quantity of produced sweat

  • Sudoriferous glands produce approximately 1 litre of sweat per day.
  • During excessive sweating, production can reach or even exceed 10 litres per day. Hyperhydrosis is a condition that causes excessive sweating.


  • Let us take the example of increased physical activity: heat accumulates thus increases the temperature of the body.
  • In order not to exceed a constant temperature of 37 degrees, perspiration regulates the body.
  • During thermoregulation, sweat coming from the sudoriferous glands evaporates via the pores of the skin.

Perspiration and smell

  • The sweat secreted by the sudoriferous glands is odourless.
  • The bad smells of perspiration, which are sometimes offensive, come from the presence of bacteria on the skin surface, which are nourished by perspiration.

The 2 types of sudoriferous glands

Each sudoriferous gland, located under the skin, is linked to a pore.
It has the form of a long hollow tube composed of cells.

There are 2 types of sudoriferous glands, the eccrine glands and apocrine glands.

Eccrine glands

  • They cover most of the body.
  • They are numerous around the head, the palms of the hand and the plants of the foot.
  • They are functional from the time of birth

Apocrine glands

  • Apocrine glands are not found in all parts of the body.
  • They are located in the groin and underarm areas.
  • They become active from the onset of puberty.