I have heavy periods with large clots and very painful cramps, what might be causing this?

Painful,heavy period: This is a common problem that can be dealt with by your pcp or gynecologist. It can be a variety of things including fibriods, endometriosis, dysfunctional uterine bleeding, or even pelvic inflammatory disease. Usually your doc will take a complete history, do a pelvic exam, and will consider an ultrasound. Treatment, like most things, depends on the cause of the painful, heavy periods.