Period pain is real—and (as you’ve probably noticed), not created equal. We all have one friend who hardly notices when Aunt Flo’s in town, and another one who calls into work sick because of bad cramps.
Menstrual cycles vary—in length and intensity, says Alyssa Dweck, M.D., an assistant clinical professor of obstetrics, gynecology, and reproductive science at the Mount Sinai School of Medicine, “We have a couple of benchmarks that we often give people,” she says. The typical cycle, she explains, is between 21 and 35 days, and the typical period is between two and seven.
Some ladies have horrible periods because of a medical condition calledendometriosis, says Dweck. It happens when tissue that normally lines the uterus grows outside of it—and there are about 176 million cases of it worldwide. But otherwise healthy women can have worse-than-normal cycles, too.
Here, six reasons your period could be lighter—or heavier—than your girlfriends’.
1. Your Diet Stinks
So you fell off the wagon for a few months—it happens. But a lousy diet doesn’t just affect the scale. “If women have a few months where their diet is really bad, that can alter menstrual flow,” says Dweck. One studyof school-aged girls found that students who ate more junk food also suffered from more premenstrual symptoms. Other research demonstrates that good-for-you nutrients—like omega-3s and calcium—reduce period pains.
2. Your Age Is to Blame
“For the first years after menstruation begins, there is no ovulation and longer cycles are common,” says Mamta Mamik, M.D., an assistant professor of obstetrics, gynecology, and reproductive science at the Icahn School of Medicine at Mount Sinai. As we age, periods normally become more regular and shorter, she adds. That is until your 40s or 50s. Some women experience uncomfortable and haphazard periods as they enter perimenopause—the stage right before menopause, says Dweck, who adds that this could include worsening pain or bad bleeding.
3. You Don’t Exercise—or You Exercise Too Much
There’s a fine line when it comes to exercise and your period. “Women who do not exercise at all may have worse periods than women who doexercise,” says Dweck. The good news is that the fix may be as simple as little movement. Ladies with bad cramps who exercise usually ease their cramping—cardio can improve your flow and probably lighten yourperiod, she says.
Just don’t take it too far: “Excessive exercise can lead to absent or reduced periods due to the effect on the hypothalamus, which can suppress periods,” says Mamik. This, she adds, has to do with a low body mass index (BMI)—which can lead to amenorrhea (a.k.a. total lack of aperiod).