Our body has two types of sweat glands. Most of the sweat glands secrete a mixture of water and salt.
The two glands are: eccrine and apocrine. Eccrine glands are present in most part of the body, and typically secrete sweat that is mostly made of water. Their purpose is to keep body cool when we are exposed to heat or enduring intense exercise.
Apocrine glands, however, are located in targeted areas of the body— the armpits, for example — and they don’t really do much to cool down the body. These glands in the armpit region and groin release oily substances.
Both these sweat glands produce odorless substances. So, these substances are not the reasons for the odor. It is the bacterial population that loves the substances.
These bacteria feed on these substances and excrete – releasing the telltale stench. This causes that bad odor for which person next to you make faces.
It is better to give attention to cleanliness of the body, if not remember what bacteria does.