Why Do Breasts Become Bigger before Menstruation?

A scientific explanation of why breast increase in size and become more sensitive before menstruation.

Hormones are the reason. Higher level of estrogen can cause a histamine-like effect on microcirculation (microcirculation is the blood flow through small blood vessels). Increased breast blood flow some days before the menstruation is the result.

Breast volume can increase by 6 to 12 inches! The feeling of tension is caused by proliferation (proliferation is fast division or reproduction of cells) of glands under the influence of estrogen and progesterone.

During menstruation the hormone level drops. Lobuli (microscopically small gland pouches) get smaller, and lacteal tubes get narrowed. The smallest breast volume is between the 5th and 7th day of menstruation.