The breasts are made up of fat, connective tissue (that supports and gives shape to the breast) and glandular tissue (that contains lobes and ducts).
The lobes (also called milk glands) are where breast milk is produced. The lobes are connected to the nipple by a network of channels called milk ducts. These are for carrying milk to the nipples when a women is breastfeeding.
The breast tissue extends into the lower armpit (axilla). The armpits contain a collection of glands called lymph nodes (sometimes called lymph glands), which are part of the lymphatic system. The lymphatic system is part of the body’s natural defense against infection and disease. Lymph nodes are small and are connected to each other by a network of tiny vessels (lymphatic vessels). These carry a fluid called lymph, which contains cells that help fight infection.
It’s common for a woman’s breasts to be a different size or shape from each other. They change throughout a woman’s life, often because of hormones. Breasts feel different at different times of the month – for example, just before a period they may feel lumpy. As a woman gets older, her breasts may become smaller and feel softer.