Why do some people's heads sweat especially when they eat?

Can the head sweat especially when eating?

This can be analyzed in two ways.

Exceptional ability to sweat on the head while eating.

Eating with only the head sweating profusely.

Why do some people sweat so much when they eat?

Human sweat glands and sweating

There are three types of sweat glands in humans, macrohidrosis, microhidrosis, and parietal microhidrosis, which appear only in the armpits after puberty.

When we talk about sweating, we are referring to the secretion of watery sweat from the small sweat glands that cover the entire body.

Humans are the second most heat-resistant animal after camels, and this super heat resistance is due to the powerful sweating ability contributed by sweat glands all over the body, which can carry away the heat generated by the body, especially during strenuous exercise.

Humans are also given the ability to regulate body temperature by this super sweating ability and have gained unparalleled long-distance running ability on earth, and because of this super long-distance running ability and run at the top of the food chain.

This shows how important sweating is to human beings.

The whole body distribution of sweat glands

Although small sweat glands are found throughout the body, the distribution of sweat glands is not uniform in different parts of the skin.

It is estimated that there are between 2 and 5 million sweat glands throughout the human body, with the density of sweat glands on the palms and soles of the feet being the highest, at about 200-700/cm2 - the "material basis" for the exceptional sweating on the palms and soles of the feet.

The density of sweat glands in other parts of the skin is between 60-120/cm2. The other parts of the skin are much less dense.

Causes of sweating

Physiological sweating in humans can be divided into two categories.

Thermal sweating, where the body's need for rapid heat dissipation due to the external environment and/or heat load generated by the body is the basic stimulus for sweating, and where a large amount of rapid heat is dissipated through sweating to maintain a stable core body temperature.

Emotional sweating, where emotions such as fear and anxiety stimulate sweating through sympathetic excitation.

The sweating of the head caused by eating mainly involves heat sweating and is not about emotional sweating.

Factors affecting sweating

Heat load

It is known that heat sweating in the body is regulated by the body temperature center located in the anterior hypothalamic preoptic area in response to internal and external heat load stimulation.

The degree of heat dissipation demanded by the heat load directly determines the threshold of sweating, the amount, and the rate of sweating.

Simply put, "the hotter you get, the more you sweat".

Body fluid volume and blood circulation status

If a person is dehydrated, the amount of body fluid is insufficient and the circulation is impaired, which can directly affect the ability to sweat.

For example, non-exertional pyrexia, which is called severe heat stroke, is caused by the loss of excess body fluids without replenishment due to prolonged sweating and severe circulatory failure resulting in no body fluids available for sweating, and the unrestricted and rapid increase in body temperature after the loss of body temperature regulation.

Of course, in the daily state, this effect is very weak.

Influence of sweat gland morphology and quantity

Sweat production depends on the number, size, thermal sensitivity, and overall activity of sweat glands.

These vary greatly among individuals.

In terms of sweat gland size, it can vary by a factor of 5 from person to person and from one skin area to another. The larger the sweat glands, the higher the sweating rate, which determines the huge differences in sweating rates between individuals and between different areas of the skin of the same individual.

As mentioned above, there are significant differences in the distribution of the number of sweat glands in different parts of the skin, with the most densely distributed parts being, in order, the palms of the hands and soles of the feet, the forehead, the forearms, the back, and other parts being relatively low.

Effect of local skin temperature

Although there are differences between individuals, local skin temperature has a significant effect on sweating. This is something that people have experienced and it goes without saying.

The head is particularly sweaty when eating

If you sweat all over your body during a meal, but your head is especially sweaty, there are several reasons for this.

The temperature of the eating environment is high, and the body is subjected to the heat load that requires sweating to dissipate heat.

For example, it is easy to sweat profusely when eating in summer; on the contrary, eating cold meals in the snow in winter will not sweat in any case.

Eat hot meals and drink hot drinks. "Eat while it's hot" is a deep-rooted "health" belief that is prevalent in the country, which naturally leads to sweating during meals.

Eat "hot" foods. Hot" spices like chili peppers, garlic, and pepper contain chemical components that activate the capsaicin receptors to produce heat and pain, and sweating, so eating these "hot" foods is naturally more likely to The sweating is naturally stimulated by eating these "hot" foods.

In this case, some people are particularly prone to head sweating, mainly due to.

The sweat glands in the head, especially in the forehead, are particularly densely distributed, or perhaps the head sweat glands are particularly large; or, these people's head sweat glands are particularly sensitive to heat load and the above "hot" food stimuli.

Also, do not forget that the mouth for eating is also long in the "head", whether it is hot rice or "hot" food, but also by "heating" the local skin and stimulating the head It is easier to sweat.

Only the head sweats profusely when eating - "taste sweating"

If the rest of the body does not sweat during a meal, but only the head and face sweat, with significant localized flushing of the skin, and the sweating is not related to the ambient temperature or the food eaten, then a rare condition called "gustatory sweating" is involved.

"Gustatory sweating, also known as Frey's syndrome, is a disease state first described by the German physician Lucja Frey (1889-1943) through a compilation of literature from the 1700s on the subject, mainly involving local sympathetic and parasympathetic disorders of the head and face. It results from a disorder of local sympathetic and parasympathetic innervation of the head and face.

It is mainly seen in patients with parotidectomy and is caused by the regeneration of some severed gustatory nerves that mistakenly attach to innervate the facial sweat glands.

Therefore, this sweating is limited to the local skin and is not directly related to heat or the food eaten, but almost exclusively to "eating", hence the term "gustatory sweating".

It has been found that in some patients with advanced diabetes after significant diabetic nerve damage has occurred, bilateral "taste sweating" can occur as a result of local sympathetic and parasympathetic nerve involvement in diabetic neuropathy.

Of course, this is a very specific condition and has nothing to do with daily sweating of the head during meals.