The initial stage of breast development in girls is mainly characterized by larger nipples, deeper areolas and larger breasts, which may be accompanied by symptoms such as breast swelling and pain. As each person’s breast fibrous tissue and fat content is different, the shape and size of the breast in the development process also exists some differences. 1, nipple enlargement: girl breast development first manifested as a simple nipple bulge, gradually increasing in size spherical, at this time may be accompanied by local itching or slight pain, should avoid scratching, so as to avoid local skin ulceration infection affect the development. At this time, you can choose a comfortable bra or small tank top, and pay attention to minimize the friction of clothing; 2, areola deepening: areola is a darker ring of skin around the nipple, before the development of the breast is light pink or light brown, with breast development can gradually deepen to brown or dark brown, and the area gradually increased. In the surrounding areola can appear raised mound, is the normal areola gland, can secrete lipid substances, play a role in lubricating the nipple, to prevent the nipple and areola skin damage infection; 3, breast enlargement: due to hormonal changes in the body so that the mammary gland development, in the process of gradual development and expansion of the breast, can be touched under the nipple small hard nodes, the breast gradually increased in hemispherical or pendulous shape, tense and elastic, often accompanied by tenderness or Breast swelling is a normal physiological phenomenon. Breast development generally begins at the age of 10 and matures over 3-5 years, reaching a peak at the age of 25. Since the first menstruation is on average 2-5 years later than breast development, breast development can be affected by menstruation. Factors such as elevated estrogen levels and hypertrophy of ductal epithelial cells in the lobules of the breast may often cause premenstrual breast swelling, firmness, and enlargement, and lumps can be palpated in the breast, but they can be relieved after menstruation ends; such symptoms are often cyclical, and most girls can continue breast development after menarche.