What Does My Period Blood Say About Me?

According to some forms of ancient Chinese medicine, a woman’s menstrual discharge is interwoven with her qi, or life force. If her qi is disrupted — by stress or disease or internal discord—those issues may manifest as irregularities in her menstrual bleeding.

While Western doctors don’t talk a lot about their patient’s “life force,” they agree some attributes of a woman’s menses could be a tip-off to underlying health conditions — both good and bad.

“The average woman has 400 to 500 periods in her lifetime, and most go off without a hitch,” says Dr. Linda Bradley, an OB/GYN and surgeon with Cleveland Clinic. While there’s a lot of woman-to-woman variation in terms of timing and volume, Bradley says normal menstrual bleeding lasts three to seven days, and comes on every 24 to 35 days. And “bleeding” is not exclusively blood; it’s a mixture of mucous, blood and tissue from the lining of your uterus.

The color and consistency of a woman’s menses can vary, so in most cases, those characteristics aren’t reliable indicators of any specific health issue, says Dr. Nanette Santoro, chair of obstetrics and gynecology at the University of Colorado School of Medicine and a member of the Endocrine Society.

One textural exception: “Clots are not supposed to form in menstrual blood,” Santoro says. Your uterus contains enzymes that should break up any clots. If some are showing up in your menses—especially if they’re large, about quarter-sized—that’s a sign of an unusually heavy bleed, which is something you should tell your doctor about, she says.

Some other signs of a heavy menstrual bleed include having to change pads more than twice an hour for four hours, or a period that lasts longer than eight days, Santoro says. “If you’re changing your pad every 20 minutes, or you can’t go to work, or you’re waking up in the middle of the night to change your pad, that’s aberrant,” Bradley adds. She says that kind of heavy bleeding could be nothing—or a sign of benign uterine polyps or fibroids, disorders of the muscle wall or lining of the uterus, hormone imbalances or even cancer.

Returning to color, a brownish or rust-colored tint can result from taking birth control pills or using an IUD, and neither is concerning, she says. But any kind of noticeable odor is. “An offensive smell could signal vaginal infection or a sexually transmitted disease,” she says. Experiencing pain or fatigue with your period are also reasons to talk with your doc. Ditto light periods or going several months without a period. Bradley says pain or period absences could signal unhealthy weight gain or malnourishment. “Anorexia, bulimia, or very heavy exercise without proper nutrition can all cause dysfunction,” she says.

In some cases, hormonal imbalances—whether caused by pregnancy, menopause or a thyroid condition—could also lead to period hiccups. That’s also true of diabetes, liver disease, or chronic diseases, Bradley explains. “It’s good to remember that regular cycles happen because your body is making an egg,” she says. If something’s up with your health, your body may decide making that egg isn’t such a hot idea, and so you might experience a wide range of menstrual abnormalities.

Rather than scrutinize your period blood for any unusual characteristics, she recommends keeping an eye out for deviations from your normal flow or schedule. “You know your body, and you know its pattern,” she says. Like a random headache, one particularly heavy or light period isn’t something to freak out about. “But if you notice a change that lasts more than one cycle, see your doctor,” she says.