How does breast have lump to return a responsibility

summary

My girlfriend is 20 years old, but she has a hard lump in her two breasts. It doesn't hurt to pinch it lightly with her hand. She can slide. What's the matter with hard lump in her breasts? Let's take a look at the following.

How does breast have lump to return a responsibility

First: it's normal. But usually don't squeeze it hard. Especially during ovulation. This is what happens to every girl. Breast development is early or late.

Second: however, breast size is still affected by nutritional status and genetics, and it is related to body shape. The breast is mainly filled with fat, so those who are thin have smaller and flat breasts; those who are short and fat have larger and higher breasts. 　

Third: under the synergistic effect of estrogen and progesterone, pituitary prolactin and adrenocortical hormone, breast development, fat accumulation in breast tissue, breast gradually plump, nipple enlarged and protruded, nipple and its surrounding areola pigmentation.

matters needing attention

Generally, even at the end of childhood, under the stimulation of a small amount of estrogen, mammary duct cells proliferate, and the breast is slightly uplifted. After entering the middle of puberty, the ovaries play a physiological function. One follicle develops and ovulates every month, and secretes hormones and progesterone.