Women with menstrual migraines who also have chronic migraines can be successfully treated with hormonal therapy, according to a study by Drs. Calhoun and Ford published in journal Headache. Surprisingly, controlling menstrual migraines led to improvement in chronic migraines as well. Chronic migraine is defined as a headache with migraine features that occurs on more than 15 days each month and it affects a staggering 4%-5% of the population. Hormonal therapy usually consists of taking an oral contraceptive continuously for many months, thus eliminating menstrual periods and often headaches and PMS symptoms. Oral contraceptives should not be taken by patients who have visual aura - visual disturbance that usually lasts 30 minutes and precedes the headache.