A tampon is summer’s MVP when you want to enjoy a dip in the pool while on your period: You don’t have to worry about any sort of blood-in-the-water situation or deal with a sopping wet pad.
But the same thing that makes a tampon so functional—its absorbency—can pose a potential risk after you get out of the water. “Just as period blood can wick down to the outside of a tampon, water can wick up into the vagina [when you’re swimming],” Mary Jane Minkin, MD, a board-certified ob-gyn and clinical professor of obstetrics, gynecology, and reproductive sciences at Yale School of Medicine, tells SELF.
If you’re not a little careful, this extra moisture can cause some trouble for your vagina. Here’s why it’s super important to change your tampon after you take a dip in the pool, float down a river, or plunge into those ocean waves, according to ob-gyns.
It isn’t a great idea to leave anything wet hanging around your vulva.
Having a tampon in your vagina—whether you’re swimming or not—creates the ideal setting for microorganisms like bacteria to multiply: It gets wet while absorbing period blood (and other vaginal secretions) and your body temperature makes it warm. All of this is fine assuming you’re changing your tampon every four to eight hours. But when you leave it in longer than that, you raise your risk of irritation or infection, as well as a rare (but serious) condition called toxic shock syndrome, where bacteria release toxins into the bloodstream.
Going for a dip in the pool, even for a short burst, only boosts how moist (sorry) things are down there. Water absorbed via both the outermost base of the tampon and the string creates an environment that stays damp post-swim, Kenosha D. Gleaton, MD, a board-certified ob-gyn in Charleston, South Carolina, and medical advisor for the perinatal health brand Natalist, tells SELF. That extra moisture primes the area for bacteria and yeast to thrive, which also ups your chances of irritation or infection. That’s why Dr. Gleaton always suggests you change your tampon (and ideally out of your wet swimsuit too) within an hour of swimming.
When it comes to any of these risks, “it’s really something already in the person and not something being transferred from pathogens in the water that we’re concerned about,” Dr. Minkin explains. (Simply put, the wet tampon sets up an ideal opportunity for the microorganisms you’re already hosting to multiply.)
That said, water moving up into the vagina via a wet tampon can also carry some not-so-great hitchhikers, Dr. Gleaton adds, like other types of bacteria, salt, or chlorine, depending on whether you’re swimming in a lake, ocean, or pool, respectively. And because your vagina is absorbent, you could theoretically soak up some of that stuff (particularly if you’re chillin’ with the wet tampon in for a while), which may cause a rash or irritation down there, Dr. Gleaton says. The good news is, there’s no solid research to suggest that a wet tampon from, say, a dip in the ocean is any more risky than one from any other body of water, or vice versa, Dr. Minkin says.