During each menstrual cycle, breast tissue sometimes swells because hormonal stimulation causes the breast's milk glands and ducts to enlarge, and in turn, the breasts retain water. The breasts may feel swollen, painful, tender, or lumpy a few days before menstruation. Breast pain and swelling usually ends when menstruation is over. The average age of women who have cyclical breast pain is 34 years old. Of all women who experience breast pain, two thirds experience cyclical breast pain.
Physicians often have patients chart their pain to determine whether the pain is cyclical.
Though cyclical breast pain is usually related to the menstrual cycle, stress may also affect hormone levels and influence breast pain. Non-cyclical breast pain is far less common than cyclical breast pain and is not related to a woman's menstrual cycle. Woman who experience injury or trauma to the breast or those who undergo breast biopsy sometimes experience non-cyclical pain. Non-cyclical pain is most common in women between 40 and 50 years of age. Usually, non-cyclical breast pain does not indicate breast cancer, though women should discuss the condition with their physicians.