Does Perspiration Always Smell?

The human body has two types of sweat glands -- eccrine and apocrine -- and they produce two different types of sweat, both odorless. Eccrine glands are present all over the body, and secrete a sweat that is mostly water, designed to keep the body cool during intense physical activity. Apocrine glands are located in the armpits and the groin, and they release a milky solution of proteins and lipids that has very little smell on its own. However, when this substance combines with the ordinary bacteria that reside on human skin and hair, it produces the rather unpleasant smell that we associate with body odor.

Do you smell something?

• Excessive perspiration is called hyperhidrosis. The phenomenon of little or no perspiration is called anhidrosis. Changes in sweat production could be a sign of a medical problem.
• Deodorants cover up odors, while antiperspirants are designed to stop perspiration. Some new sweat-fighting products contain aluminum compounds that temporarily block sweat glands.
• At some point in human evolution, microbe-induced smells may have served a purpose. Animal studies, for example, have found that such body odors can actually promote reproduction.