We've all been through the special hell of menstrual cramps, but if you've experienced the added hurdle of lower back pain during your period, you're not alone. The phenomenon of "period back"—a term we've just coined—is both alarmingly common and rooted in science. According to Rebecca Brightman, M.D., an OB-GYN in Manhattan, the discomfort is a direct result of prostaglandins, otherwise known as fatty acids that cause uterine contractions.
"Prostaglandins produced during your period cause the uterus to cramp and contract, resulting in back pain," she tells InStyle. "It's the same phenomenon as in labor but on a much smaller scale. With labor contractions, you can feel the contractions in the back, and then they move toward the front."
But if the uterus is located toward the front of the body, why do we feel the effect in our backs? It could be referred pain, says Sherry A. Ross, M.D., a Los Angeles-based OB-GYN and author of She-ology: The Definitive Guide to Women's Intimate Health. Period. "Due to nerve fibers in the pelvis, you can perceive pain in another part of your body," she says. Ross estimates that 75 percent of women experience moderate back pain during their periods.
Though generally perceived as a normal side effect, lower back pain during a period can also signal problems. "If the pain worsens over time, it could be endometriosis, which is characterized by severe menstrual pain," says Sarah Yamagutchi, M.D., an OB-GYN in Los Angeles.
The good-(ish) news: To combat period back, the same methods used to treat period cramps work. Advil, Motrin, and other non-steroidals disrupt the cycle of prostaglandins and ease pain, says Brightman. And though exercising may be the last thing anyone wants to do during their period, the endorphins can help counterbalance bloating and PMS.
In addition to natural remedies, like a heating pad or hot water bottle, Ross recommends using a period tracking app, like Clue or Flo, so you can prophylactically take an ibuprofen before your period even starts. She also says that filling your diet with calcium-rich foods like cheese, kale, and tofu can reduce cramping.
VIDEO: Emily Ratajkowski Gets Real About Her Period
If the pain becomes severe, Yamagutchi recommends asking your doctor about the birth control pill, which is known to lessen blood flow and decrease cramps. "If it gets to the point where it's interfering with your life, then you have to do something about it," she says. Otherwise, grab a heating pad, hop on the elliptical, and sleep it off.