Standard breasts are hemispherical in shape, symmetrical on both sides, full, soft, flexible and straight, and may sag with age. Under normal physiological conditions, as a woman enters puberty, at the age of 10 to 11 years, the female breasts will gradually develop and enlarge, and reach a steady state around the age of 20 years, with normal development demonstrating symmetrical double hemispherical full breasts. When a woman enters pregnancy and breastfeeding, it is regulated by hormone levels in the body. As the breasts develop and milk is stored in the breasts, a woman’s breasts enlarge to some degree and usually shrink to a certain extent after lactation is over. In addition, as a woman slowly ages, the shape of her breasts slowly sags and dries out. In daily life, women should carry out regular breast self-examination, observe the appearance of the breasts through a mirror, and then touch the breasts with fingers and abdomen to check whether there are nodules and lumps in the breasts and whether there is any obvious pain when touching.