A third nipple (also called supernumerary nipples, in the case of multiple nipples) is a condition in which you have one or more extra nipples on your body. This is in addition to the two typical nipples on the breasts. The third nipple, or the presence of multiple nipples, is also known as polymastia or polythelia.

Is polythelia normal?

Polythelia and Polymastia

Supernumerary nipples (polythelia) and supernumerary breasts (polymastia) are relatively common congenital abnormalities with an incidence of approximately 0.2% to 2.5% (polythelia) and 0.1% to 1.0% (polymastia) (see also Chapter 61).

What causes polythelia?

Polythelia typically occurs during development in the womb, but the exact cause is unknown. This condition can be inherited and run in families.