Normally, your vagina is a self-cleaning, harmonious balance of healthy bacteria and yeast.
Yeast infections (science-y name: candidiasis) happen when things get out of whack and the yeast grows a bit out of control. Yeast infections can happen in your vagina, on your penis, or even in your mouth (that's called thrush).
Several things can contribute to this kind of imbalance, like: a weakened immune system, changes in your hormone levels throughout your menstrual cycle, antibiotics, cortisone, and other medicines, pregnancy, or a natural reaction to another person's genital chemistry.
Note that swimming isn't on this list. However, yeast infections and other kinds of vaginitis can thrive in damp and warm environments, so wearing a wet bathing suit for a long time after you go swimming can increase your chances of getting a yeast infection — especially in the summertime. So keep things dry by bringing a change of underwear (ideally cotton underwear) when you go swimming.
Visit a doctor or nurse, like the staff at
your nearest Planned Parenthood health center, to get the right diagnosis and treatment if you're worried. Stay cool!
— Emily at Planned Parenthood