When breasts first start to develop, there are usually symptoms such as breast enlargement, nipple enlargement and areola color deepening. 1. Enlargement of breasts: When girls enter puberty, due to changes in hormone levels in the body, the breasts will begin to develop and gradually become larger, and there may be hard knots under the nipples, and slight pain may be felt in the breasts. 2. Enlarged nipples: When girls’ breasts first begin to develop, the nipples will also change and may begin to bulge, usually in a spherical shape. 3. Deepening of areola color: When girls’ breasts start to develop, the color of the areola will also change, and the color will gradually deepen, from light pink or light brown to dark brown, and the area will also gradually increase. Girls should take good care of their breasts during development, such as keeping a good mood, wearing underwear in time, and choosing to wear soft underwear, so as not to cause stimulation to the breasts. Parents should pay attention to observation during the child’s body begins to develop, if there are any abnormal symptoms, should go to the regular hospital in time.