areolae

Areolae are the two circular pigmented areas that surround the nipples on human breasts and on the breasts of many mammals. They vary in size, color, and texture, and may darken with age, hormonal changes, pregnancy, or breastfeeding. The areola’s skin is typically thicker and more pigmented than the surrounding breast skin.

Anatomy and structure: The areola contains glands of Montgomery, which secrete lubrication during pregnancy and lactation to help keep the nipple and surrounding area moisturized. It may also house sebaceous glands. Smooth muscle fibers in the region contribute to nipple erection in response to stimulation or cold. The nipple itself sits at the center of the areola.

Development and variation: Areolar size and coloration differ widely among individuals and populations. Hormonal changes during puberty, pregnancy, and lactation can alter appearance. Skin tone, genetics, age, and hormonal status influence the degree of pigmentation and textural features of the areolae.

Function: The areolae play a role in breastfeeding by providing lubrication and sensory cues that help the infant locate the nipple. The surrounding tissue may also aid in protection and skin conditioning during lactation.

Clinical note: Changes in the appearance of the areolae—such as abrupt color changes, new lumps, skin lesions, or unusual nipple discharge—should be evaluated by a medical professional to rule out underlying conditions.

Other uses: In broader biology, the term areola can describe any small circular area of differing color or texture on an organism or object; areolae of the breast are the most commonly referenced example.