Flat chest if you want to develop again can be done through exercise, dietary supplements, physical therapy, etc., but the effect is minimal. Surgical breast augmentation can effectively improve breast shape. 1. Exercise. Adhere to jogging, swimming and other aerobic training to effectively improve the physical quality of the whole body, thereby promoting the development of breasts. In addition, chest strength exercises such as chest expansion exercises can enhance the strength of chest muscles and lift the chest. It is recommended to exercise under the guidance of professionals. 2. Food supplement. Moderate supplementation of collagen-rich foods such as pig’s trotters and collagen may assist in the secondary development of breasts, but the effect is minimal. It is recommended to decide the dietary supplement program under medical advice. 3. Physical therapy. Massage and acupuncture of the relevant points on the chest can help breast development by promoting blood circulation, and its effect varies from person to person. It is recommended to do so under professional guidance. Generally speaking, the above conservative means are quite weak in promoting the secondary development of breasts. If the person concerned has the need to improve the appearance of the breasts, the most effective clinical treatment is surgery. It is recommended to go to a regular hospital for professional assessment before undergoing autologous fat cell filler, silicone implantation, etc. to improve breast shape.