Body odor is influenced by many factor and can influence other people in different ways.

Not only sweat glands but also sebaceous glands and apocrine sweat glands produce substances contributing to body odor. Sebaceous and apocrine become active at puberty. This as well as many apocrine glands being close to the sex organs points to a role related to mating. In humans the armpit regions seem more important than the genital region for body odor which may be related to human bipedalism. The genital and armpit regions also contain springy hairs which help diffuse body odors.

Factors such as food, drink, and diseases can affect body odor. An individual’s body odor is also influenced by lifestyle, gender, genetics, and medication.

Body odor is influenced by the actions of the skin flora, including members of Corynebacterium, which manufacture enzymes called lipases that break down the lipids in sweat to create smaller molecules like butyric acid. These smaller molecules smell, and give body odor its characteristic aroma. Propionic acid (propanoic acid) is present in many sweat samples. This acid is a breakdown product of some amino acids by propionibacteria, which thrive in the ducts of adolescent and adult sebaceous glands. Because propionic acid is chemically similar to acetic acid with similar characteristics including odor, body odors may be identified as having a vinegar-like smell by certain people.[citation needed] Isovaleric acid (3-methyl butanoic acid) is the other source of body odor as a result of actions of the bacteria Staphylococcus epidermidis, which is also present in several strong cheese types.