Breast development can generally be divided into five stages. Different stages of breast development can mark different stages of female growth and development. 1. Only small nipple bulges. This period is called puberty and is mostly below the age of 9. 2. Both breasts and nipples are elevated, shaped like mounds, and areolas appear. This period occurs between the ages of 9 and 11. 3. The entire glandular areola of the breast gradually grows into the full shape of the breast. This period occurs between the ages of 12 and 13. 4. The glands near the areola may protrude over the entire enlarged breast to form a second-stage mound, and the breast rises significantly above the chest. This period occurs between the ages of 13 and 14. 5. The breast line is full, the areola is well defined, and the nipple is large and prominent. This period occurs from the age of 15 to female maturity. This is why it is important to seek medical attention when discomfort occurs during female growth and development.