Sweating and its relationship with genetic factors What we need to know

14.11.2024

Sweating is a physiological process that begins for various reasons in response to an increase in body temperature. It serves to self-cool the body and prevent overheating. Sweating also provides skin hydration, protection from skin microbes, maintenance of salt and electrolyte balance, removal of toxins and metabolic waste products from the body, and more.

Table of Contents

Where does sweat occur?

The skin is the largest organ of the human body. It is composed of several layers: outer, thin layer - epidermis, middle thick layer - dermis and inner layer subcutaneous cells or hypodermis.

All layers are richly supplied with blood vessels and lymphatic vessels. Hair follicles, sweat and sebaceous glands are also located in the dermis (the middle layer of the skin). Touch and pain receptors (nerve endings) are placed in the dermis.

Sweat glands are located in all areas of the skin, all over the body, although they are more abundant: on the palms of the hands and feet, on the forehead, in the armpits.

Sweat glands are a type of apocrine (exocrine) glands that secrete the product of animal activity - sweat on the surface of the skin.

Human skin contains two types of sweat glands: eccrine sweat glands, which release sweat directly on the surface of the skin and Apocrine sweat glands - which are located in areas of the skin rich in hair follicles, such as: armpits, groin, scalp.

Eccrine sweat glands respond to the increase in body temperature and provide temperature regulation by releasing sweat. Their number is several million on the surface of the skin, and this number does not change during life. Apocrine sweat glands are mainly activated during puberty.

What does sweat consist of?

99% of sweat produced by eccrine sweat glands is water. The remaining 1% is sodium chloride. Sodium and chlorine are the main micronutrients in sweat, but sweat also contains other substances, such as:

Potassium
Vitamins
Traces of calcium, magnesium, copper, zinc iron
proteins and amino acids
Toxins: heavy metals, bisphenol and others

The sweat produced by the apocrine sweat glands is much thicker and, in addition to salt and sodium chloride, contains proteins, glucose, lipids, and ammonia.

Why sweat?

The main function of sweat is to regulate and cool body temperature. In addition, the function of sweat is:

Protection against skin infections by releasing antimicrobial substances together with Ofltan
Maintaining water-salt and electrolyte balance of cells
Keeping the surface of the skin moist
Removal of metabolic waste products and toxic compounds from the body

When does sweat break out?

Sweating occurs whenever the body needs to cool down. Excessive sweating characterizes such conditions as:

physical activity
Drinking caffeinated beverages
Eating spicy food
taking alcohol
Tobacco consumption
Fury
Stress, anxiety and psychomotor agitation
High temperature and illness
Taking specific medications
Pregnancy
Menopause and others

How much sweat is released?

The amount of sweat produced varies with gland activity, environment, age, gender, weight, type of clothing, and other factors. The degree of sweating varies from person to person. With age, the production and release of sweat decreases. Taking into account the above factors, the amount of sweat secreted by the sweat glands ranges from 0.5 to 2.0 liters per hour.

Hyperhidrosis, i.e. excessive sweating

Increased activity of sweat glands leads to hyperhidrosis, i.e. excessive production of sweat.

There are several variants of hyperhidrosis:

Focal hyperhidrosis: Excessive sweating is the most common form. It is common in young people and is characterized by excessive sweating in the armpits, hands and feet, head, waist.

Generalized hyperhidrosis: Increased sweating is expressed throughout the body. Common in middle-aged adults. As a rule, the causes of this form of sweating are:

Pheochromocytoma (adrenal gland tumor)
Anaphylaxis (generalized allergic reaction)
Anxiety
Tumors (Hodgkin's lymphoma, leukemia, bone tumors)
Carcinoid syndrome
Medicines: Antidepressants, hormonal drugs
Diabetes (low or very high blood glucose)
heart failure
infections
Obesity
Hyperthyroidism
Lung diseases
Menopause
Conditions associated with pituitary tumors (acromegaly)
Pregnancy
spinal cord injury
stroke
Drug and alcohol use

Asymmetric hyperhidrosis - that is, sweating in only one half of the body - has been described. As a rule, it is associated with neurological disorders (Horner's syndrome - as a result of damage to the brain stem, spinal cord and other organs).

Night sweats are a typical condition in menopause and premenstrual period.

Excess production of sweat may cause skin irritation, itching. In case of violation of hygienic conditions, it is possible to multiply microflora and develop an inflammatory process.

Diagnosis begins with an evaluation of symptoms and history to determine the cause of excessive sweating.

Decreased or absent sweating

Decreased sweating - hypohidrosis or its complete absence - anhidrosis is associated with various conditions, such as:

Burns and other skin scars
Connective tissue diseases (Sjogren's disease, scleroderma)
Dehydration of the body
drug addiction
Alcohol-induced neuropathy
Neuropathy associated with diabetes, multiple sclerosis
Neurological disorders, such as - Horner's syndrome - ptosis, miosis and decreased sweating in one half of the face; Harlequin syndrome - absence of sweat in one half of the face, neck and chest
Skin diseases (eczema)
Genetic disorders: Fabry disease, hypohidrosis ectodermal dysplasia and others.

How do genetic factors affect sweating?

Some genetic diseases - Fabry's disease, hypohidrosis ectodermal dysplasia and others - are characterized by a sharp decrease in sweat production. Under the influence of genetic factors, the characteristics of the smell change during the release of sweat.

Fabry's disease

Fabry disease is a rare genetic disorder (lysosomal storage disease) in which the activity of sphingolipid (molecules with a lipid structure) degrading enzymes is impaired and sphingolipids accumulate in blood vessels and tissues. Mainly the kidney, heart, brain and skin tissues are damaged and a descriptive symptom complex develops:

Paresthesias of the limbs: a sharp pain or burning sensation in the projection of long nerves of the limbs
A sharp reduction or complete absence of sweat
Angiokeratomas - dark purple spots on the skin of the lower body.
Corneal dystrophy - distortion of the cornea, without loss of vision. Eye vascular pathologies.
Gastrointestinal disorders: abdominal pain, episodes of constipation and diarrhea.
Tinnitus – ringing in the ears and/or hearing loss
Swelling of the lower extremities
General weakness and feeling of fatigue
Headache and dizziness
Nausea-vomiting
delayed puberty
Heat intolerance

The disease may be accompanied by life-threatening complications:

Kidney failure
Peripheral neuropathy
heart failure
stroke

Fabry disease is caused by a mutation of the alpha-galactosidase A (GLA) gene, which is involved in the synthesis of the enzyme alpha-galactosidase. As a result of the mutation, an insufficient enzyme is obtained, or its complete absence is observed, which leads to clinical manifestations of the disease.

The (GLA) gene is located on the X chromosome, so the disease is more common and more severe in men than in women (men only have 1 X chromosome. In women, a healthy GLA gene on the second X chromosome balances the mutation and the disease is milder).

Hypohidrosis ectodermal dysplasia

People with hypohidrosis ectodermal dysplasia are characterized by a decrease in the number of sweat glands, or a sharp decrease in function. The disease is characterized by:

Peculiarities of the development of facial features
Underdevelopment of teeth
Scaly hair on the head and body

This pathology is caused by the X chromosome EDA with gene variations. In addition, mutations in the EDAR, EDARADD and WNT10A genes, which are located on autosomal chromosomes, are involved in the development of birth defects. These genes ensure the normal development of skin, hair, nails and sweat glands.

Trimethylamine

Trimethylamineuria is a rare genetic metabolic pathology known as "fish-bone disease". The only symptom of the disease is the fishy smell of the skin, exhaled air, sweat and urine.

The cause of this smell is trimethylamine, a substance that is produced in the intestines as a result of the breakdown of food by bacteria. Typically, the flavin-containing enzyme monooxygenase-3 converts trimethylamine to an odorless substance. FMO3 As a result of the changes developed in the gene, the activity of the enzyme monooxygenase-3 decreases, the accumulation of trimethylamine in the body and its excretion with urine, sweat and exhaled air are observed. The pathology is autosomal recessive, that is, a person must inherit a gene mutation from both parents in order for this condition to manifest.

Cystic fibrosis

Cystic fibrosis is a genetic disease caused by a mutation in the CFTR gene that causes defects in a cell membrane protein that regulates the concentration of water and salts in cells. In addition to the main symptoms (thick and sticky mucus in the respiratory and digestive tract, etc.), cystic fibrosis is characterized by increased sweating. Salts released with sweat cannot be absorbed from the surface of the skin, therefore the skin is more "salty" than normal.

body odor

ABCC11 The gene is related to the function of sweat secretion by apocrine sweat glands. Clinical studies of sweat studies have established that polymorphisms of gene variants determine certain amounts of specific components in sweat, which are determinants of specific body odor. The lower the amount of these components in sweat, the less specific body odor is expressed.