A girlfriend with small breasts may be caused by heredity, diet, and hormone deficiency, which can be improved by means of surgery, dietary adjustments, and hormone adjustments. If the small breasts are caused by genetic factors, they can be improved by means of breast fillers. Women who are in need of breast fillers need to go to regular hospitals and undergo surgical treatment under the operation of professional doctors. If small breasts are caused by dietary structure, it can be improved by adjusting the dietary structure. Breasts are made up of mammary tissue and fat. Eating too much protein and fiber foods will lead to low body fat content, so you should eat vitamin-rich foods to improve. If small breasts are caused by hormone deficiency, they can be improved by hormone adjustment. The development of mammary glands is related to estrogen content. Suffering from pituitary tumors or ovarian diseases will lead to a decrease in estrogen and small breasts. Patients can take oral synthetic estrogen drugs such as progesterone, etc. The use of drugs must be used under the guidance of a doctor. Generally speaking, small breast size is a normal physiological phenomenon, which is not harmful to health, and there is no need to worry too much.