The areola is the darker part of chest skin that surrounds the nipple, in both men and women. Varying in size according to the individual, it generally has a diameter of 3 cm but may cover the entire surface of the breast, or be barely visible. The areola is covered in several areolar glands that protect the breast against infection
and desiccation. The areola also contains a muscle
that allows the erection
of the nipple.