Sudore

Sudore, or sweating, is the production of a transparent, salty liquid by sweat glands in the skin. Its primary function is thermoregulation: as sweat evaporates from the skin, it promotes cooling of the body. Sweat also contributes to the excretion of small amounts of electrolytes and waste products.

The body contains two main types of sweat glands. Eccrine glands are numerous and widely distributed, especially on the palms, soles, and forehead, and they produce a watery sweat in response to heat and physical activity. Apocrine glands, concentrated in the armpits and groin, secrete a thicker fluid that becomes odorous when metabolized by skin bacteria. The composition of sweat is largely water but includes electrolytes such as sodium and chloride, along with trace amounts of potassium, urea, lactate, and other organic compounds.

Sweating is regulated by the autonomic nervous system. The hypothalamus senses core temperature and activates sympathetic cholinergic pathways to the eccrine glands, increasing sweat rate during heat, exercise, fever, or emotional stress. Individual variation exists due to genetics, acclimatization, hydration status, and environmental conditions.

Clinical aspects include hyperhidrosis, a condition of excessive sweating that can be focal (often underarms, palms, or feet) or generalized. Hyperhidrosis may be primary (idiopathic) or secondary to medical conditions or medications. Anhidrosis or hypohidrosis is reduced or absent sweating, which can impair heat dissipation and raise the risk of heat-related illness. Treatments for hyperhidrosis range from topical antiperspirants and oral medications to botulinum toxin injections, iontophoresis, and, in severe cases, surgical options. Sweat is otherwise a normal, ubiquitous bodily fluid essential for temperature regulation and skin health.