Adolescent breast tenderness usually lasts until a woman’s puberty is completely over, probably after the age of 20. Breast swelling and pain during puberty is mostly related to changes in estrogen levels in the body. The breast is an endocrine organ and there are receptors for endocrine hormones on the breast tissue, such as estrogen and progesterone, which increase significantly during puberty, acting on the corresponding hormone receptors on the breast and stimulating the proliferation of breast tissue. At this time, the growth of breast tissue is the fastest in the entire female life span, and some people may even experience edema in the interstitial mammary glands. As this occurs, women may feel breast swelling and pain during puberty, and it tends to occur periodically with the menstrual cycle. The hormone levels gradually fall back at the end of puberty, around the age of 18-20, when the phenomenon gradually decreases or even disappears. However, women may also experience slight breast tenderness each subsequent menstrual cycle to a much lesser extent than during puberty, which can be negligible or even not felt. Breast tenderness usually does not require special treatment, if the tenderness is particularly pronounced, affecting work and life, to exclude breast disease, it is necessary to go to the hospital for special examination.