Breasts can be painful during development, as women begin to enter the pubertal stage of development between the ages of 9-13 years old, their breasts can become swollen and painful, due to the effects of changing hormone levels in the body during puberty. It may also be accompanied by breast development, lumps in the breasts, and pain. By the end of puberty and the onset of menstruation, the pain will gradually disappear as the breasts mature. In addition, breast pain is not excluded to be caused by breast hyperplasia, there will also be lumps and pain in the breast, especially after anger and overwork, the symptoms will be more obvious, it may also be caused by breast fibroids and other diseases. To summarize, breast development during puberty will appear pain, which is a normal physiological phenomenon. If abnormal pain occurs, it is best to go to the relevant departments of the hospital to do a careful examination, and then targeted treatment.