sebum
Meaning of sebum: Sebum is an oily substance made by skin glands that lubricates and waterproofs skin and hair.
Definition of sebum
Sebum is an oily, waxy substance produced by sebaceous glands, small structures found within the skin that are especially concentrated on the face and scalp. Sebum is made up largely of lipids, including triglycerides and wax esters, and it travels along the hair follicle to reach the surface of the skin.
Sebum helps lubricate and waterproof the skin and hair, reducing water loss and providing some protection against friction and minor environmental irritants. Sebaceous gland activity is influenced by hormones, part of why sebum production commonly changes during puberty and can vary between individuals and body regions.
When sebum combines with dead skin cells and blocks the opening of a hair follicle, it can contribute to the development of acne, particularly when bacteria normally present on the skin multiply within the blocked follicle, prompting inflammation of the surrounding tissue.
Used in a sentence
Excess sebum production was noted on examination of the patient's skin.
Good to know
Sebum production naturally varies by body region and by individual, so an oily complexion on its own does not necessarily indicate a skin condition requiring treatment.
Word origin
Where “sebum” comes from
From Latin sebum, meaning tallow or grease, describing the substance's oily texture.