Apocrine Sweat Glands
Deep-seated glands in the armpit hair follicles that secrete a thick, completely odorless fluid. The resulting smell is created entirely by bacteria breaking down this secret, not by the sweat itself.
These are specialized skin glands located deep within the hair follicles of the armpit that secrete a thick, chemically odorless fluid. Unlike glands producing dilute salt solutions, these release complex secretions that become the primary nutrient source for bacteria. The familiar armpit odor is not produced by the sweat itself but is synthesized entirely by bacteria breaking down these secretions.
What this means in real life
When a teenager gets nervous before a presentation, their armpits produce a distinctive smell—not from regular sweat, but from apocrine glands responding to stress hormones, which bacteria then break down into odor.
What it isn’t
These are not the main cooling sweat glands on your body. Eccrine glands, which cover most skin and activate when you're hot, handle temperature regulation; apocrine glands are fewer, deeper, and serve different functions.
Commonly misused online
People often call all body odor 'sweat smell,' but apocrine secretion itself is odorless—the smell comes from bacterial breakdown. Social media conflates the two, suggesting sweat itself stinks.
Based on 2 reference sources, including NIH material. Last verified July 11, 2026.