Yes, it’s certainly possible. Many sexually transmitted diseases (including chlamydia, gonorrhea, HIV, and human papillomavirus) can be asymptomatic, meaning you have it in your body but there are no noticeable signs. You can also mistake STD symptoms (vaginal discharge or painful urination, say) for indications of another condition, like a yeast or urinary tract infection—especially if, as in some cases, the symptoms don’t surface until months after you become infected.
Untreated STDs can have serious consequences, such as pelvic inflammatory disease (PID), infertility, or cervical cancer, which is why it’s so crucial to use condoms and get tested regularly for STDs if you’re sexually active and not in a long-term, monogamous relationship. (I know, I know—flashback to high school sex ed class.) FYI, there’s a “newer” STD you should ask your doctor about, too. Experts have determined that the bacterium Mycoplasma genitalium, or MG, is transmitted via sexual contact. Like chlamydia and gonorrhea, MG infection has been linked to PID and inflammation of the cervix, yet more than half of women (and nearly all men) who tested positive for it in a recent study reported no symptoms. Testing for MG is not yet widely available, so your doctor may need to send your sample to a special lab or research center for analysis.
Health’s medical editor, Roshini Rajapaksa, MD, is assistant professor of medicine at the NYU School of Medicine.