If you are 20 years old and still have flat breasts, the more obvious way to enlarge your breasts is to undergo breast augmentation, or you can try exercise methods, etc., which are both healthy and safe. In addition, if you feel that your breasts have not been developing, you also need to seek medical advice to exclude whether there are endocrine diseases and other conditions, and if there is such a possibility, listen to the physician’s advice to actively treat. 1, breast augmentation: there are more breast augmentation methods, usually based on autologous fat filling injection method, because the filler comes from the patient’s own, the rejection reaction is smaller. Breast augmentation can also be done by placing breast implants, but there may be rejection reactions. However, such methods are invasive operations and have certain risks; 2, sports: such as chest expansion exercises, push-ups, butterfly swimming, yoga, etc. Although sports cannot promote fat accumulation in the chest, they can make the pectoral muscles get exercise, which in turn makes the chest shape more beautiful and also prevents the chest from sagging. Exercise will also consume fat in other parts of the body, making the shape more coordinated; 3, treatment of primary diseases: if there is an endocrine disease, the imbalance of sex hormone secretion in the body leads to 20 years old or flat chest, you need to actively treat the primary disease and regulate the level of hormones in the body; 4, other methods: daily shower with warm water rinse chest, maintain good rest, choose the right bra, etc., can promote blood circulation around the chest It is also beneficial for chest development. Some people believe that breast acupuncture, massage and other methods can promote breast form to increase, but there is no relevant research to confirm, can refer to the discretion. However, it is not recommended to use or consume breast enlargement products because they usually contain a lot of hormones, which is not good for your health. For thinner people, who have flat breasts due to low body fat content, they can eat fat-rich foods appropriately. However, breast aesthetics should not be judged by size, and a correct aesthetic should be established.