The Scary Truth About the Most Common STI in the U.S.

More than 1.6 million Americans got chlamydia last year. And those are just the ones who got tested.

The real number's way higher because 80% of people with chlamydia have no symptoms. They're walking around spreading it without a clue. Dr. Michael Shen from NYC Health + Hospitals says most people don't even know they have it.

Chlamydia's the most common bacterial STI in the United States. Dr. Orchideh Alexander from Atlantic Health in New Jersey says it's so prevalent that the CDC's basically given up on containing it. They're just trying to get people tested at this point.

What Chlamydia Actually Is

It's a bacteria called Chlamydia trachomatis. There are other types of chlamydia bacteria, but this is the one that spreads through sex.

When symptoms do show up - which remember, they often don't - it takes one to several weeks after you got infected. You might get burning when you pee, weird discharge from your penis or vagina, pain during sex, or if you're really unlucky, testicular or rectal pain.

Dr. Melissa Suarez from Inspira Health says women can get pelvic inflammatory disease if it's not treated. That can lead to chronic pain, ectopic pregnancy, or infertility. Definitely not something you want to ignore.

How You Get It

You get it from sex. Vaginal, anal, oral - doesn't matter. Direct contact spreads it. Suarez says it can infect your rectum and throat too if those areas are exposed during sex.

Babies can get it from their mothers during birth, which causes eye infections or pneumonia.

Who's at highest risk? Young people, people with multiple partners, anyone who doesn't use condoms consistently, and people whose partners have STIs. Basically, if you're having unprotected sex with people you don't know well, you're at risk.

Testing Is the Only Way to Know

Since most people have no symptoms, you need to get tested. They check your pee or swab your vagina, cervix, urethra, rectum or throat. The test looks for the bacteria's DNA or RNA.

The CDC recommends yearly testing for sexually active people under 25 or older people with risk factors like new or multiple partners.

The Good News: It's Curable

Antibiotics get rid of it in about a week. Shen says most infections clear within one to two weeks with proper treatment. But here's the catch - you need to tell your recent partners so they can get treated too. Otherwise, you'll just pass it back and forth like a terrible game of ping pong. Alexander says everyone needs to finish their antibiotics and avoid sex until treatment's done.

Suarez says you should get retested after four weeks to three months to make sure you didn't get reinfected. Because let's be real, people aren't great at the whole "telling partners" thing.

What Happens If You Don't Treat It

Women get the worst of it. Pelvic inflammatory disease, chronic pelvic pain, ectopic pregnancy, and infertility are all possible consequences. All from bacteria you didn't even know you had.

Men can get epididymitis, which is painful swelling in the tubes that carry sperm. Both men and women can get reactive arthritis, which causes joint pain and swelling.

If you're pregnant and have chlamydia, your baby can get it during delivery. That means eye infections or pneumonia for the newborn. Not exactly the welcome-to-the-world gift you want to give.

How to Not Get Chlamydia

Unless you are in a committed relationship and unequivocally trust your partner, use condoms every time. Shen says consistent condom use significantly reduces your risk.

Have that awkward conversation with new partners about STI testing. Yes, it kills the mood. No, that doesn't matter.

Get tested regularly if you're sexually active. Especially if you have multiple partners or your partner has multiple partners.

If you're in a relationship, both get tested before ditching condoms. Don't just assume everything's fine.

The Reality Check

The World Health Organization says over 374 million new STIs happen worldwide every year. Chlamydia makes up more than a quarter of those. It's not rare. It's not something that only happens to "other people."

Over-the-counter pain meds and heating pads can help with symptoms while antibiotics do their thing. But the best treatment is not getting it in the first place.

Here's the bottom line: if you're having sex, you should be getting tested for chlamydia. Even if you feel fine. Especially if you feel fine, since that's how most people with chlamydia feel.