Breast Anatomy

Three-quarter view of female head, neck, and chest with raised right arm showing anatomy of right breast and lymph nodes.

Breasts come in all shapes and sizes. But they all share the same features. You can learn about the parts, or anatomy, of your breasts. This will help you know what you're seeing and feeling. Then you can learn what's normal for your breasts.


The areola is a dark circle of skin that surrounds the nipple.

The nipple is the outlet for milk during breastfeeding.

Fibrous tissue supports your breasts, making them feel firm.

Lobules (mammary glands) produce milk during pregnancy and breastfeeding.

Ducts carry milk from the lobules during breastfeeding.

Fatty tissue fills the spaces around the ducts and lobules.

Axillary lymph nodes filter lymph fluid from your breast and help your body fight infection.

Ribs can be felt beneath the skin.

The clavicle (collarbone) marks the upper boundary of the breast tissue.

The sternum (breastbone) can be felt beneath the skin.

Chest muscles help move your arm.