FLAT BREAST IN WOMAN
Sometimes a woman's breasts don't develop much during puberty but she remains "flat-chested" - without any or much palpable breast tissue. Typically, flat-chested girls do have a nipple that looks swollen or elevated, but for some reason the breasts don't grow in size at all. Flat-chested girls do get pubic hair and start menstruating just normally and their breasts do have milk glands - it's just that the breasts don't grow in size like most girls.
Unfortunately experts like doctors and lactation consultants don't really know why this takes place. It is known that typically flat-chested women's hormone levels are just fine and they can often successfully breastfeed, so it may be that this represents a problem in the connective tissue inside the breast and not in the actual duct / alveoli system of the breast. It has been suggested that maybe flat-chested women's breast tissue is insensitive to normal levels of circulating hormones.
But no matter what the cause, it won't hurt to eat healthy so as to give your body the best chance to have everything working properly.
During pregnancy the breasts do usually develop more and grow in size, and flat-chested women can breastfeed and produce milk. A totally flat woman's breasts can grow to a A or even B cup during pregnancy and while breastfeeding. However, obviously with small 'storage space' the baby might need to nurse quite often.
A flat chested woman is not abnormal in the sense that her breasts are functional and can make milk. She's also not abnormal in the sense that there are many many other women out there with a flat chest (or almost that). They typically used padded bras so you don't necessarily notice it from outside unless you know the person.
It is true that a flat-chested woman's breasts did not develop as most women's, and lack the fatness, but like already noted, it is not known why this is.
Homoeopathy system of medicine works magically in this case. Homoeopathic medicine can correct flat breast and helps the normal development of breast