Where does breast tissue start and end?

Breast tissue extends from just below the collarbone (clavicle) down to the lower edge of the ribcage and across to the midline of the chest, near the sternum (breastbone). The upper and outer portions of the breast extend into the armpit (axilla) area where somebreast tissue may also be present.

It's important to note that breast tissue density and distribution can vary among individuals, and some people may have more or less breast tissue than others.