Fibrocystic Breast Condition Changes

The development of fibrocystic breast condition is apparently due to an increased estrogen-to-progesterone ratio.  During each menstrual cycle there is a recurring hormonal stimulation of the breast.  As the hormone levels fall after a few days the breasts normally return to their prestimulation size and function.  In many women these changes are so slight that clinical signs or symptoms do not appear.  In others, however, significant inflammatory processes occur.
 
The cells of a fibrocystic breast are characterized by overgrowth and enlargement, increased secretory activity, dilation of the milk ducts and scarring.  These effects may be due to increased levels of the hormone prolactin which is secreted by the pituitary gland.  Estrogen, both internally produced and in birth control pills, causes an increase in prolactin secretion.