The word is derived from the Latin for a courtyard, or little open space, and was first used in 1605 by Bauhin applied to the colored area around the nipple of the breast.

The areola is a specialized circular area of skin centered on the nipple, distinguished by its color and protruding mouths of glands. It varies greatly in size, the smallest being in the male, about one inch across, and the largest in very large breasts when the areolae may have a four inch diameter.

The epidermis (outer layer) of the areola is pigmented; two pigments are known, the brown eumelanin and the red pheomelanin. In general the virgin “white” breast has pink areolae, and the virgin “black” breast has dark areolae. Both are likely to darken in pregnancy, but this is by no means a sure test for virginity, many females of very light complexion continue with pink areolae after childbirth.

Areolar glands of Montgomery are a cross between sweat glands and mammary glands; their mouths form little hillocks in the areolae, and in the lactating breast exude a greasy substance which is protective to the skin. At the margins of the areolae the glands are more distinctly of the “sweat” character, and there may be hair bearing follicles.