Q. My menstrual cycle has been regular for as long as I can remember. But now that I've entered my late 30s, it seems to be changing. Should I be worried?
A. Not necessarily. It's natural for your period to change in response to fluctuating hormone levels. Even before you hit menopause, your ovaries gradually slow down and produce less progesterone, according to Carol Archie, M.D., an associate professor of obstetrics and gynecology at UCLA School of Medicine. This can leave you with heavier, longer, or even less frequent periods. Switching birth-control methods -- which many women do in their 30s and 40s -- may also have an impact on your menstrual flow. For example, many women get heavier periods after going off the Pill or after an IUD is inserted, Dr. Archie says.
Some menstrual changes, however, should be checked by a gynecologist or nurse-practitioner. If you experience very heavy menstrual bleeding, for instance (saturating an entire pad or tampon in less than an hour or two), this could signal a more serious medical condition, such as fibroids, endometriosis, a thyroid disorder, or (rarely) uterine cancer. According to Dr. Archie, irregular periods may be brought on by strenuous exercise, high levels of stress, or a sudden change in weight.
Another red flag to look out for: "Missing one or more periods, of course, could be a sign that you're pregnant," says Dr. Archie. If there's a chance you are, your doctor may ask you to take a pregnancy test to rule out this possibility.