izzadság

Izzadság, or perspiration, is the physiological process of sweat production by the skin’s sweat glands. It is a central component of thermoregulation and also plays a role in excretion and maintaining skin hydration.

There are two main types of sweat glands. Eccrine glands are widely distributed and produce a watery, salt-containing sweat that helps cool the body through evaporation. Apocrine glands are concentrated in the armpits and groin and secrete a thicker fluid that is metabolized by skin bacteria, contributing to body odor. Eccrine sweating is the primary cooling mechanism and can be triggered by heat and physical activity, while emotional sweating largely involves eccrine glands on the palms, soles, and forehead.

Sweat production is controlled by the autonomic nervous system, with the hypothalamus acting as the thermoregulatory center. Secretory activity is stimulated by sympathetic cholinergic nerves. The typical sweat composition is mostly water with electrolytes such as sodium and chloride, along with small amounts of urea, lactate, and amino acids; the fluid is slightly acidic.

Sweating varies with environmental temperature, physical exertion, humidity, clothing, hydration, and acclimatization. Psychological or emotional states can also influence sweating, particularly in areas rich in eccrine glands.

Clinical relevance includes disorders such as hyperhidrosis (excessive sweating), often focal and primary, and anhidrosis or hypohidrosis (reduced sweating), which can impair cooling. Diaphoresis refers to noticeable sweating associated with fever, illness, or stress. Management depends on cause and severity and ranges from topical antiperspirants to medications, botulinum toxin injections for focal hyperhidrosis, iontophoresis, and, in refractory cases, surgical options.