Migraine occurs approximately three times more often in women than in men, and research has determined that menstrual hormone changes are one of many potential triggers. Menstruation is one of the main factors that places women at risk for migraine. Although migraine headaches are equally common in young girls and boys, the number of girls affected increases sharply after the onset of menstruation. About 60% of female migraine sufferers experience menstrual migraine that occurs before, during, or immediately after the period or during ovulation. Estrogen, the female sex hormone that specifically regulates the menstrual cycle, generally causes menstrual migraine. Changes in the hormone levels of estrogen and progesterone during the menstrual cycle can trigger migraine in sufferers. Women on birth control pills may experience menstrual migraines more frequently because of the influence that oral contraceptives have on estrogen levels.

Migraine occurs more often in women than in men. Although migraine headaches are equally common in young girls and boys, the number of girls affected increases sharply after the onset of menstruation. It seems clear that certain hormonal changes that occur during puberty in girls, and remain throughout adulthood, are implicated in the triggering and frequency of migraine attacks in women. The finding that 60% of women sufferers related attacks to their menstrual cycle supports this link between female hormone changes and migraine headaches. Attacks may occur several days before or during the woman's menstrual period. There are women who also get the headache mid-cycle, at the time of ovulation. Estrogen levels fluctuate throughout the menstrual cycle. The headaches typically occur in association with drops in the estrogen level. Few women (less than 10%) have headaches only with menses. Therefore, in most women, hormones are just one of many migraine triggers.