Breast pain during development is normal, the mammary glands are also developing, starting from the appearance of secondary sexual characteristics, especially women will appear breast development, the body estrogen rising, prompting the mammary glands to continue to expand, so it will produce a painful feeling, but also should pay attention to the abnormal situation. If the size of the breasts is asymmetrical or there are asymmetrical nodules, the skin of the breasts has a different color, unevenness, or secretion of unknown fluid, etc., it should be noted and alerted. If you experience any of the above, it is best to go to the hospital and have a mammogram or other tests done to determine if there are any abnormalities. If there are any abnormalities, then choose a treatment plan as soon as possible. If everything is normal, then there is no need to be overly nervous, and you should keep a regular schedule and stay in a happy mood.