Sweat glands in action: the role of biological and environmental factors, exercise, and dermatologic conditions in sudomotor function.

Sweating is the primary mechanism for human thermoregulation, driven by eccrine gland activity under central and peripheral sudomotor control. In this review, we synthesize evidence showing that sudomotor function is shaped by biological traits (age, sex, ethnicity/ancestry), environmental exposures (regional climate, seasonality, and migration), and individual modifiers (exercise training and dermatologic disease). Environmental heat exposure induces heat adaptation, leading to short-term and long-term acclimation with contrasting effects. Short-term acclimation enhances sweat gland sensitivity and density, increasing sweat output for efficient cooling during heat stress. Conversely, long-term acclimation suppresses sweating to conserve body fluids by reducing sweat gland responsiveness and output. Regional and seasonal differences in sweating patterns are closely linked to climate adaptations. Age-related declines in sweat gland function are evident; children exhibit higher sweat gland density but lower output per gland due to immature sudomotor function. Exercise training improves sweat gland sensitivity and density, enhancing thermoregulation during physical activity. Dermatologic conditions such as atopic dermatitis and psoriasis impair sweat secretion through skin barrier dysfunction and autonomic dysregulation, exacerbating inflammation and compromising thermoregulatory efficiency. This review highlights the complex interplay between intrinsic biological traits, external environmental stimuli, and individual behaviors in shaping sudomotor function. Understanding these mechanisms can inform strategies for optimizing thermoregulation and managing sweat-related impairments in clinical settings.