Why an Extra 5-10 Pounds Is Totally Normal Sometimes

Is that skyrocketing scale just water weight? Find out from Shape how your monthly visitor affects your number.

You've been exercising and eating healthy, but the scale just threw you a curve ball, clocking in at five more pounds than last week. Don't worry; if your shocking weigh-in lands the week before your period, you can chalk it up to water weight, reassures Raquel Dardik, M.D., gynecologist at NYU Langone Medical Center. "Weight gain happens five days before your period, but you'll be back to normal once you start," she explains. (Find out What Your Period Means for Your Workout Schedule.)

Pre-period water weight can range from half of a pound to 10 pounds, usually averaging around five for most women, Dardik explains. Why? The hormone progesterone—essential in the early stages of pregnancy—is to blame: when there's no baby (aka when you get your period), these levels fall. As a side effect, each cell in your body retains an extra microscopic drop of water, Dardik explains.

While it doesn't lead to weight change, bloating caused by gas can magnify the situation by making you feel a size bigger. (Find out The Truth About PMS, Weight Gain, and "Fat Days.")

Before you ask, yes, you can figure out exactly how much weight gain is to blame on your monthly visitor, but it's better to not focus on numbers. Instead, maintain a healthy scale schedule to keep yourself in check: weigh yourself once a week, on the same day, at the same time, using the same scale. "The main thing is not to overdo it, because fluctuations in weight are common," Dardik says. (That's one of 9 Weight Loss Tricks You're Already Doing.)

Combat these side effects the way you battle all bulge: with exercise. And drink a lot of water to help get rid of water retention, says Dardik. Also try and avoid fatty foods, alcohol, and salt, which triggers your body to hold onto water, says Dardik. (So do these 5 Seemingly-Harmless Foods That Cause Belly Bloat.)

That extra weight that doesn't disappear after your period, though? This could be caused by pre-period cravings that make you hungry for salty, greasy foods, and sweets—and that kind of weight will not come off after your period, Dardik warns. So before you indulge simply because you're PMSing, think about whether you want to be carrying that extra weight post-period.

Moral of the story: check your weight, but don't be paranoid about it. And keep your chin up: Your best days are ahead of you, explains Dardik, as women usually feel at their peak in the first 7-10 days after their period.