Why do we sweat when nervous?

The body has two main types of sweat glands. Eccrine glands cover most of the body and mainly cool us down, while apocrine glands, concentrated in the armpits and groin, respond strongly to emotional stress. When you feel anxious, the fight-or-flight response floods the body with adrenaline, which activates these glands and produces the clammy, sudden sweat associated with nerves. Because apocrine sweat contains fats and proteins that skin bacteria break down, stress sweat tends to smell stronger than sweat from exercise. Evolutionarily, sweaty palms may once have improved grip for climbing or fighting, and emotional sweat may carry subtle chemical cues that others can unconsciously detect. Nervous sweating is completely normal, though for some people it becomes excessive.