OK TMI: What happens when you leave a tampon in for too long?

There are some things that are surprisingly easy to forget: Mom’s birthday (is it the 21st or the 23rd?!), turning off the oven after making banana bread, putting on deodorant during quarantine, and yes, changing your tampon. (Don’t judge.)

Well, it happens to the best of us—and, most likely, it’s NBD. But if you have a light flow and don’t want to bother changing your tampon, docs say you should think twice about ignoring the instructions on the box.

How long can you leave a tampon in, and what can happen if it’s there too long?

Most gynecologists say you shouldn’t leave one in for more than eight hours at a time. Why? Because while tampons these days are generally very safe, leaving a tampon in for too long can alter the pH of the vagina, which allows bacteria and fungi that are already living in your vagina to grow.

“Yeast and bacteria tend to thrive in moist places, with blood as a medium,” says Alyssa Dweck, MD, FACOG, a gynecologist in New York who has been voted top doctor in New York magazine and in Westchester County. “Most people have the question if they can wear a tampon overnight when they’re sleeping. You can, but if you’re a 12-hour sleeper you should plan accordingly.”

Over time, forgetting to change a tampon increases the risk of irritation and infections, including bacterial vaginosis (BV) and yeast infections, explains Jessica Shepherd, MD, FACOG, an assistant professor of clinical obstetrics and gynecology at the University of Illinois College of Medicine, in Chicago. As mentioned above, the longer a tampon is left in, the more likely it is to throw the natural balance of bacteria and yeast out of whack. You may notice a strong odor that can get quite foul (musty or fishy) due to the blood, secretions, and bacteria in the tampon, and vaginal discharge may appear brownish red or thick yellow, says Dr. Shepherd.

Because tampons are highly absorbent, Dr. Dweck adds that they wick moisture out of the vagina the longer they’re in, making tissue dry and irritated. And if you’re particularly susceptible to yeast infections, she suggests being extra careful about regularly changing your tampon and avoiding scented tampons, which can alter the pH of the vagina and increase infection risk.

Yet another key reason to change your tampon on the reg: In very, very rare circumstances, an overgrowth of certain types of bacteria, including Staphylococcus aureus (staph) and group A streptococcus (strep), can enter the bloodstream through tiny tears in the vagina and cause toxic shock syndrome (TSS). The higher absorbency of the tampon, the greater the risk—which is why doctors recommend using the lightest absorbency that handles your flow and changing tampons regularly. “[TSS] can progress very quickly and cause multi organ failure and damage,” says Dr. Dweck.

According to the Centers for Disease Control and Prevention (CDC), TSS got on our collective radars following an increase in TSS cases and deaths of healthy young American women between 1979 and 1980. The FDA began requiring tampon manufacturers to reduce the levels of certain chemicals (dioxins and rayon) used in tampons to minimize the absorbency to a safer level. Manufacturers also began adding instructions on the label advising women to change tampons frequently. By 1986, TSS cases had dropped significantly. Nowadays, TSS happens but is rare: Dr. Dweck says that she’s only seen TSS two or three times in her more than 20 years of practice, none of which were severe enough to cause death. (Nationally, rates are estimated to be about one to three cases per 100,000 people each year.)

For the record, you should be sure to regularly change your menstrual cup if you use one, too: That same moist environment can similarly lead to infections, including TSS.

Okay, so what should I do if I left my tampon in for too long?

First of all, try not to freak out. Most of the time if you leave a tampon in for more than eight hours, you’ll just need to remove it and remind yourself to be more careful.

You should, however, definitely see a doctor if you exhibit any TSS symptoms, which include unusual abdominal pain or pressure, a skin rash (which looks like a bad sunburn or red dots), or flu-like symptoms including a high fever, chills, and watery diarrhea. “Believe me, if it’s TSS you’ll be in the ER. It’s unusual to miss the symptoms,” says Dr. Dweck.

Also check in with your doctor if you have symptoms of BV or yeast infections, which include a change in vaginal discharge (BV tends to be grayish-white and foul-smelling, while yeast infections cause thick, white discharge), vaginal itching or irritation, pain during sex, painful urination, and vaginal spotting outside of your period.

“I don’t want to give tampons a bad name. Loads of women use them and there’s really no problem with them. You just have to be smart about it,” says Dr. Dweck. Hear, hear.

Written by: WellGood