5 STDs You Can Have Without Knowing It

These infections don't always cause symptoms.

Here’s the problem with all those scary stories and photos you might remember from Sex Ed class: They’re misleading. It’s very possible to have STDs with no symptoms, so telling teens that they’ll be able to tell when they’re exposed to something is both unrealistic and irresponsible.

The idea that sexually transmitted diseases (STDs) are these gross, life-altering conditions is also deeply stigmatizing, not to mention largely inaccurate. In reality, many STDs can be cured with a round of antibiotics, while others can be managed with medication. And you may never even know you have an STD, either because the symptoms are so subtle or because there are no symptoms at all.

Because of all this, many organizations actually prefer to use the term sexually transmitted infections (STIs) rather than STDs, since a disease is defined as a condition that impairs normal functioning and typically comes with symptoms or signs—which isn’t often the case with these infections. While the terms STD and STI are still typically used interchangeably, it’s worth noting that many of these ailments are, in fact, infections that come with no symptoms at all and can be cured with antibiotics. However, for consistency’s sake, we’ll continue to use the term STD throughout this article.

If you're sexually active, getting an STD is a real possibility. The CDC estimates that 20 million new STD infections occur each year in the U.S. That's why it's so important to get tested regularly, and to be honest with any new partners (and your gyno) about your sexual activity. It's even more important when you consider that condoms can't protect against all STDs and that STDs with no symptoms exist—some of which can do serious damage if they go untreated.

While some STDs, like HIV and syphilis, can hang around in your body for a bit before symptoms pop up, they're typically known for being symptomatic. In most cases, an infected person will show the telltale signs of the infection. But there are a few STDs that are actually known for being asymptomatic, which means you could never know you have them until they've spread or led to other side effects.

Here are the STDs that don't have obvious symptoms. Take this as your official reminder to not only practice safe sex, but get tested regularly especially if you have new partners or are thinking of becoming pregnant at any point later in life.

1. Human papillomavirus (HPV)

What it is: HPV is the most common sexually transmitted infection, and one of the ones that condoms can't always protect against. Chances are you'll have HPV at some point in your life whether or not you realize it. "You could be carrying it and passing it and not have any physical signs," Michael Cackovic, M.D., an ob/gyn at the Ohio State Wexner Medical Center, tells SELF. That's because some strains cause genital warts, but many others don't.

What you can do: If you're under 30, HPV won't be a part of your routine STD screening, because it's so common and often goes away after some time (there's no treatment for it anyway). If you're over 30, routine screening is recommended along with your Pap smear. While it's very likely you'll have the virus at some point and nothing bad will ever come from it, some strains of HPV can cause cervical cancer, which is why getting a regular Pap smear is so important. An abnormal Pap smear indicates changes in the cervical cells usually caused by HPV, and depending upon what type of abnormal cells your doctor finds, you may be tested to confirm HPV was the cause.

2. Chlamydia

What it is: Chlamydia is one of the most common STIs in women under 25. It's also known as a "silent" infection, because most people will never experience symptoms. "Abnormal vaginal discharge or a burning sensation during urination may occur several weeks after sex with an infected partner," says Meike L. Uhler, M.D., a reproductive endocrinology and infertility specialist at the Fertility Centers of Illinois. But at that point, the infection has probably been going on for a while and is moving up the urinary tract and into the body. It's easy to confuse these symptoms for a less-serious infection, like a yeast infection or bacterial vaginosis, so it's important to see your ob/gyn if you notice changes in discharge, pain, or burning. Bleeding between periods, lower back and abdominal pain, and pain during sex are also potential symptoms. But, again, it could come with no symptoms at all.

"If left untreated, chlamydia can spread to the uterus and fallopian tubes, resulting in pelvic inflammatory disease (PID)," Uhler adds. In fact, untreated chlamydia is a common cause of PID, according to the U.S. Department of Health and Human Services. Pelvic inflammatory disease can cause scarring in the fallopian tubes, which can lead to blockage and permanent damage that causes infertility. The CDC notes that each year, 24,000 women become infertile because of an undiagnosed STD.

Scarring can also cause an ectopic pregnancy, which can be life-threatening for both mom and baby. "Chlamydia can also cause premature birth and can be passed to a baby during delivery, causing eye infection or pneumonia," Uhler explains. Chlamydia also increases a woman's risk of contracting HIV from an infected partner.

What you can do: The CDC recommends annual chlamydia screening for women under 25, pregnant women, or anyone at risk for chlamydia (which really just means you’ve had a new partner or you’re not 100 percent sure of your partner’s STD status). This might sound like overkill, but remember: Chlamydia can be an STD with no symptoms, meaning your partner could have it and have no idea. The good news is that chlamydia is easy to treat with antibiotics, so if you catch it early (before it causes any damage) you'll be completely cured.

3. Gonorrhea

What it is: Similar to chlamydia, gonorrhea is most common in sexually active women under 25, and the majority will never experience symptoms. "While they are two different diseases, chlamydia and gonorrhea are commonly diagnosed together," Uhler notes, and the mild symptoms (if they ever show up) are similar: breakthrough bleeding, vaginal discharge, and burning and pain that can easily be mistaken for a bladder or vaginal infection. Typically, these are symptoms of the bacterial infection spreading further from where it originated.

If gonorrhea goes unnoticed and untreated for too long, it can lead to pelvic inflammatory disease, scarring, and damage to the reproductive organs. It can also increase your risk of getting HIV, and in extreme cases, cause life-threatening infections in other parts of the body such as the blood, brain, heart, and joints. Gonorrhea during pregnancy raises the risk of premature birth, low birth weight, miscarriage, and serious health complications (like blindness and blood infection) for the newborn.

What you can do: The CDC recommends annual gonorrhea screening for women under 25, pregnant women, and anyone at risk for gonorrhea (which really just means you’ve had a new partner or you’re not 100 percent sure of your partner’s STD status). Again, this might seem unnecessary, but it’s completely possible to have gonorrhea without knowing it. The good news: Gonorrhea is also curable with antibiotics, you just need to know you have it first.

4. Herpes

What it is: Herpes is a viral infection that can present on your mouth or your genitals. It’s caused by two types of viruses: herpes simplex virus type 1 (HSV-1) and herpes simplex virus type 2 (HSV-2). HSV-1 typically causes oral infections while HSV-2 typically causes genital infections, but it’s possible to have oral herpes caused by HSV-2 or genital herpes caused by HSV-1.

According to the CDC, about one out of every six people between 14 and 49 years old in the U.S. has genital herpes. While most people think of herpes and automatically picture painful, red blisters, not everyone gets those. In fact, it's estimated that up to 90 percent of people with HSV-2 are never diagnosed. While herpes is most infectious during an active breakout, it can still be spread when there are no sores present. Plus, condoms won't necessarily protect you from the virus if it's present on skin that falls outside of the condom.

What you can do: The best way to reduce your risk of herpes is to use barrier methods like condoms and dental dams correctly every time you have sex. That said, these methods don’t cover everything, so it’s possible to still get herpes even if you practice safe sex.

Oddly enough, routine herpes screening is actually not recommended by the CDC. This is because there is no cure for herpes, though there is treatment to manage the symptoms. So there’s really not much you can do until you have symptoms. If you don’t have symptoms, keep practicing safe sex (whatever that means for your situation) and talking to your partners about their STD status and screening history. If you’re with someone who has herpes, make sure to take precautions (like using a condom or dental dam and possibly avoiding sexual contact when they’re having an outbreak).

If you believe you may have been exposed to herpes, talk to your doctor about that. If you have any sores or symptoms they can take a swab test of that, or they can do a blood test that looks for herpes antibodies. If you have herpes, your doctor will prescribe a medication to manage symptoms and talk to you about reducing the risk of transmission to your partners.

5. Trichomoniasis

What it is: This little-known STD is actually pretty common and it’s caused by a parasite. According to the CDC, only about 30 percent of people with the STD show any symptoms, so it’s very likely that you could have this STD with no symptoms. When it does cause symptoms, those can include: itching, burning, redness, soreness, uncomfortable urination, and vaginal discharge that’s different and comes with a fishy odor. For men, the symptoms could include: itching and irritation, a burning sensation after peeing or ejaculating, and a discharge from the penis.

If left untreated, trichomoniasis can increase the risk of acquiring other STDs, including HIV. It can also pose risks if you’re pregnant, as babies born to people with trichomoniasis are more likely to be born preterm or with a low birth weight.

What you can do: You can lower your risk of getting trichomoniasis by using condoms every time you have sex, but it’s possible to be infected even if you practice safe sex. While routine trichomoniasis screening is not recommended for everyone, the CDC does recommend screening in certain high-risk areas of the country and in people with a high risk of infection (like if you have multiple sex partners, have had STDs in the past, or are a sex worker). The good news is that if you have trichomoniasis, it can be cured with a round of antibiotics. However, it’s possible to get infected again, so you’ll want to make sure your partners get treated, too.