Breast development is too big. If you want to make your breasts smaller, you can use physical exercise, surgical treatment, and improve your dietary structure. 1. Physical exercise: Breasts are made up of mammary and fatty tissues, and weight loss through physical exercise can reduce chest fat. At the same time, you can properly carry out chest expansion exercise, so that the pectoralis major muscle becomes tight, to a certain extent, can be thin chest. 2. Surgery: When the chest is too big, partial mastectomy can be used, but the surgery is traumatic, so the patient should consider carefully and under the operation of a professional doctor for chest reduction surgery. 3. Improve dietary structure: too large breasts may be due to the effect of estrogen, you can reduce the consumption of hormonal foods or drugs to avoid too large breasts. In most cases, the development of breasts is a normal physiological phenomenon, patients should not worry too much.