Common Acne Terms To Know


A broad term that refers to any abnormality in the tissue of an organism, often used to describe different forms of acne.


The oily substance produced by sebaceous glands, designed to moisturize and protect the skin but can lead to clogged pores when produced in excess.

Comedo (plural: Comedones)

The initial stage of an acne lesion, which is essentially a clogged pore. A comedo can be open (blackhead) or closed (whitehead).


An open comedo, where the trapped sebum and dead skin cells have been exposed to air, causing oxidation and turning it dark.


A closed comedo, where the trapped sebum and dead skin cells are beneath the surface of the skin.


A small, solid, raised bump on the skin that signifies inflammation or infection. It's typically less than one centimeter in diameter and does not contain pus.


An elevation of the skin containing pus. It generally has a whitish or yellowish head and is often surrounded by a ring of red, inflamed skin.


A larger, solid, painful lump beneath the surface of the skin. Unlike a pustule, a nodule is harder and deeper.


A severe form of acne lesion, which is a large, pus-filled bump deep within the skin. Cysts are painful and can lead to scarring.

Inflammatory Acne

Refers to acne that results in lesions like papules, pustules, nodules, or cysts, which involve redness and swelling.

Non-Inflammatory Acne

Refers to acne that includes blackheads and whiteheads but does not involve redness and swelling.


A type of hormone that increases during puberty and can cause the sebaceous glands to enlarge and produce more sebum, leading to acne.

Glycemic Index

A measure of how quickly a food causes blood sugar to rise. High glycemic index foods are thought to contribute to acne.


A class of synthetic and naturally occurring Vitamin A compounds and derivatives that are used in skin care and treatment of acne.

Understanding these terms can help you communicate more effectively with healthcare providers and make informed decisions about skincare.