When you're breastfeeding, there are natural oils that are secreted by the Montgomery Glands (
little bumps visible on your areola), which prevent bacteria from breeding.
«Common changes include more
visible veins on the breasts, darker and larger areolas, enlarged and more firm nipples, stretch marks on the breasts, breasts feeling more firm, the appearance of
little bumps on your areola called Montgomery's glands, nipple and / or breast tenderness, and growth of the breasts themselves.»