We still get a kick out of the scene in Mean Girls when Coach Carr warns the class, “If you do touch each other, you will get chlamydia. And die.” As much as this hyperbolic movie scene makes us laugh, it’s also a reminder that we strongly believe sex education should be just that — education — rather than fear mongering. Many STIs are extremely common, treatable, and preventable.

But we get it: it’s easy to lose sight of the rational when you have sex with someone new and something smells or looks a little unusual afterwards. Plus, scrolling through Google search results resembling Coach Carr statements isn’t exactly helpful when it comes to finding answers. To help you brush up on your STI knowledge and understand exactly what to do when things don’t feel or look right, we put together this no-freak-out guide to three common STIs.

What’s the difference between STDs and STIs?
Great question. As you probably know, “STI” stands for “sexually transmitted infection” while “STD” stands for “sexually transmitted disease.” Even though these acronyms are often used interchangeably, there’s a difference between an infection and a disease. Here’s what experts at Planned Parenthood have to say about this: “Medically, infections are only called diseases when they cause symptoms, and many STIs don’t have any symptoms. So that’s why you may hear people say STIs — it’s technically more accurate, and also reminds people that there are often no symptoms so it’s important to get tested.”

Human papillomavirus (HPV)
According to the Centers for Disease Control and Prevention (CDC), HPV is the most common STI. 79 million Americans are infected with HPV and at least half of sexually active adults will be infected with it in their lifetime. (If you get it, you’re definitely not alone.) The CDC says, “You can get HPV by having vaginal, anal, or oral sex with someone who has the virus. HPV can be passed even when an infected person has no signs or symptoms.”

A lack of symptoms is why some women don’t find out they have HPV until their pap smear (which tests for HPV and cervical cancer) comes back abnormal. Don’t worry (this is the no-freak-out guide, remember?): most of the time, HPV goes away on its own and does not cause any symptoms or health issues. But in some cases, HPV can cause genital warts or types of cancer.

If your pap smear comes back abnormal, it doesn’t mean you have cancer. As this Healthline article explains, it simply means there are abnormal cells on your cervix, some of which could be precancerous. Your doctor may recommend getting pap smears more frequently. They also may suggest a colposcopy, which helps your doctor more closely examine your vaginal and cervical tissues. In some cases, your doc may need to take a sample of your cervical tissue by performing a biopsy.

If you weren’t vaccinated as a preteen (the FDA recommends girls and boys should receive the vaccination no younger than 11 years old), you still can up until you’re 26 years old. (The FDA has only approved the vaccination for people under 26.) If you’re older than 26, getting a routine pap smear, HPV test, or both at your provider’s office can prevent and detect cervical cancer caused by HPV. Keep in mind, the HPV test is only available for women ages 30 and up.

Using latex or polyurethane condoms (use the latter if you’re allergic or sensitive to the former) the right way each time you have sex is a simple way to lower your chances of contracting HPV. (Keep in mind that lambskin condoms don’t protect against STIs, only pregnancy.) However, HPV can infect areas that aren’t covered by a condom, so it’s not a sure-fire prevention method. Only having sex with someone who isn’t sleeping with anyone else can also help reduce your likelihood of getting it. But even people with only one lifetime sex partner can get HPV, if their partner was infected with HPV. Right now, HPV testing is only available for females, not males. Getting vaccinated if you’re younger than 26 or routinely getting pap smears or HPV tests if the best way to take care of yourself.

Chlamydia
“Chlamydia is a SUPER common bacterial infection that you can get from sexual contact with another person,” write experts at Planned Parenthood. “Close to 3 million Americans get it every year.” According to Planned Parenthood, chlamydia is spread through vaginal, anal, and oral sex. The infection is carried in semen and vaginal fluids and can infect the penis, vagina, cervix, anus and urethra, as well as the eyes and throat.

Experiencing pain or burning while peeing or during sex, noticing foul-smelling or yellow-colored vaginal discharge, bleeding between periods, pus or a watery or milky discharge from the penis, or swollen and tender testicles are a few symptoms of chlamydia. But here’s the thing: most people with chlamydia don’t have any symptoms and feel totally normal, so they may not even know they’re infected. Who knew STIs could be so sneaky?

This is why regular STI testing, especially if you have multiple partners, is important. If left untreated, chlamydia can lead to a host of issues like infertility, pelvic inflammatory disease (PID), and ectopic pregnancy (a pregnancy outside the womb). The best way to prevent chlamydia is by using a latex or polyurethane condom correctly, or being in a mutually-exclusive sexual relationship with a partner who’s been tested and received negative STI results. Considering that treating chlamydia only requires a prescribed antibiotic medication from a doctor, why not get tested?

Gonorrhea
Commonly referred to as “the clap,” gonorrhea is another extremely common STI that impacts men and women and is spread through bacteria exchanged during oral, anal, or vaginal sex. The CDC estimates that approximately 820,000 new gonococcal (the fancy adjective form of gonorrhea) infections occur in the U.S. each year.

Gonorrhea can infect the genitals, rectum, and throat. The symptoms for both men and women may go unnoticed, which is why STI testing is critical. If you do have symptoms, they may appear similar to those of chlamydia. Both men and women might experience burning while urinating. Men with gonorrhea can have green, white, or yellow discharge coming from the penis, while some women notice increased amounts of vaginal discharge or bleeding between periods. However, most women are asymptomatic. If any symptoms are noted, it’s easy to mistake these very mild signs for a bladder or vaginal infection.

When in doubt, get tested. If left untreated, gonorrhea can lead to infertility, PID, or ectopic pregnancies. Like chlamydia, gonorrhea requires a prescribed antibiotic medication to treat.

Want to take a wild guess as to how you can prevent gonorrhea? Condoms! We know, we know — we sound like a broken record. But hey, at least we’re not Coach Carr. By all means, touch each other! Just make sure you’re effectively using protection or are sexually monogamous with someone you know is uninfected.

English Taylor is a San Francisco-based women’s health and wellness writer and birth doula. Her work has been featured in The Atlantic, Healthline, Refinery29, NYLON, and Modern Fertility. Follow English and her work at https://medium.com/@englishtaylor or on Instagram at @englishtaylor.