A body has between two and four million sweat glands lying deep in the skin. They are connected to the surface by coiled tubes called ducts. You perspire constantly, even without exercise. Sweat is a liquid made from 99% water and 1% salt and fat. Up to a quart of sweat evaporates each day.
When your body becomes overheated, you sweat more. The evaporation of sweat from your skin cools your body down.
When you’re frightened or nervous (imagine being pinned under heavy weights) you also sweat more. Your palms and forehead begin to sweat. So do the soles of your feet and your armpits. These are sites where sweat glands are most abundant.
So why do you smell when you sweat? You may notice the smell mostly comes from our pits (hence why we put deodorant there). This is because the apocrine glands produce the bacteria that break down our sweat into “scented” fatty acids.
“Apocrine sweat by itself does not have an odor, but when the bacteria that lives on our skin mixes with apocrine secretions, it can produce a foul-smelling odor,” Haimovic says.
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