Do you know why our hands sweat when we get nervous?

Have you noticed that sometimes when we get very nervous or are about to face a challenging situation, our palms begin to sweat? This reaction, while uncomfortable, is quite common, and happens to even the most confident people in the world. However, why does this occur precisely with the hands?

According to the staff at Today I Found Out, hands sweat in some situations due to the stimulation of a specific type of sympathetic nervous system-related sweat gland, which controls the body's responses in fight and flight situations. But to know how all this happens, one must first understand the complex functioning of these glands.

Gland Types

According to Today I Found Out, humans have three different types of sweat glands: the eccrine, the apocrine and a third more developed gland that has characteristics of the previous two. The eccrines constitute the majority of the sweat glands present in the body, and their main function is to control body temperature.

They focus especially on some areas of the body - such as the soles, forehead, and palms - and when stimulated, they release a colorless, odorless liquid that evaporates and therefore cools our temperature when it is very high. . Apocrine glands, on the other hand, concentrate in the genital region and armpits, and produce a less fluid and oily substance that is released into the hair follicles.

The third type of gland, which has eccrine and apocrine characteristics, also concentrates in the armpits and genital region, and is capable of producing sweat seven times faster than the other glands. Incidentally, there is a condition called hyperhidrosis, in which individuals suffering from it sweat more than normal, and it is believed that the problem may be related to the functioning of these "mixed" glands.

You may have wondered about the unpleasant smell that sometimes comes with sweat. In fact, the odor is the result of the action of bacteria present in certain regions of the body, which react with the fluids released by the body producing the bad smell.

And the hands with that?

In situations where the body needs to lower body temperature - such as when we are doing physical activities, for example - neurotransmitters (such as dopamine, epinephrine, norepinephrine, and acetylcholine) release that activate the functioning of the sweat glands. But what about hands?

When the eccrine glands - the ones that focus on the forehead, feet and hands, remember? - are stimulated by the nervous system to regulate body temperature, this order is sent from an area of ​​the brain called the hypothalamus. On the other hand, when we get nervous, the stimulus is sent from the neocortex and limbic centers. The magic of hand sweating occurs due to the response sent from these different brain regions.

Thus, when the stimulus is triggered by emotional stress, at first the eccrine glands in the feet, face, armpits, and hands are activated, and blood vessels constrict. However, when the response is sent by the hypothalamus, the opposite occurs, ie, a dilation of the vessels, which in turn causes an increase in blood flow near the skin to help reduce body temperature.

and why this happens?

The most widely accepted theory of why humans evolved to present this complex system suggests that emotional sweating - and increased moisture in the hands - would help to improve sensitivity in the event that it is necessary to fight an enemy, hunt or scale. any surface.

Widespread sweating - which occurs in response to stimulation from the hypothalamus - would help lower body temperature if these intense physical activities happen. Moreover, in this second case, odors and pheromones would also be released, which would not only send signals to enemies or animals, but would also indicate to potential partners who would be the best natural candidate for mating.

* Originally posted on 11/07/2013.

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