Sweat is an essential part of normal bodily function. This liquid made up of water, sodium and a mix of minerals acts as the body's radiator fluid. When your internal temperature rises, glands in your skin release sweat onto its surface, where it evaporates, cooling the skin and lowering your body temperature [source: Porter].
Human sweat glands come in two forms: eccrine sweat glands, which cover most of our skin, and apocrine sweat glands, which are concentrated in the scalp, armpits and groin. The two glands produce different types of sweat. Eccrine glands produce the sweat that cools your body when its core temperature rises, while apocrine glands release a thicker, fattier substance in response to stress, such as a tense argument or an intense sporting event. Scientists suspect apocrine sweat contains pheromones, hormonally driven indicators of mood or fertility. But most people recognize apocrine sweat as the source of body odor; naturally occurring bacteria on the skin consume the substance, and their waste is what causes the unpleasant smell after an intense workout [sources: Baker, Mayo].
Both types of sweat gland share some structural features. The base of a sweat gland is a coiled structure nestled in the border between the skin's thick middle layer, or dermis, and the subcutaneous layer of fat at the base of the skin. A series of ducts leading up from the coiled structure channel the gland's secretions to the skin's surface.
The difference between eccrine and apocrine glands, beyond the type of sweat they produce, comes in their location. While eccrine glands open directly onto the skin's epidermis, or outer surface, apocrine glands release their sweat at the root of hair follicles. Consequently, infections of the apocrine glands are often referred to as folliculitis [source: Baker].
The structure and function of sweat glands plays a key role in many types of sweat gland infections. Read on to learn how sweat glands can become victims of their own design.