STDs are common, and they’re pretty easily spread through penetrative sex, other sexual contact and sometimes through other ways. That means a lot of people have STDs. We would share a stat here but in reality, stats would miss a lot of people or make estimates. That’s because it’s so easy for people not to know they have an STD.

You may think you would notice telltale signs, but that’s the problem—in many cases, you won’t see signs of an STD even if you have one. It’s the same with your partner—they could have an STD without either of you knowing it, exposing you to transmission. Even a doctor’s exam won’t necessarily show you have an STD if you’re not showing symptoms. The only way to truly know whether you have one is to get tested.

But just like it’s common to have an STD, it’s common to not get tested. That’s why we don’t have an accurate picture of STD rates—many people haven’t gotten tested, so there’s no way to know for sure if they have an infection. Why don’t more people get tested for STDs? Maybe you can relate to some of these answers.

They don’t think they need one.

A lot of people think there’s pretty much no way they could have an STD. Maybe they’ve only had oral sex but not penetrative sex. Maybe they’ve only been with one partner or always use protection. Or maybe they believe myths about STDs and don’t feel like they’re the type of person who could get one. But these scenarios don’t fully protect from STDs. They can still spread through oral sex and through just one encounter with one infected person. Protection reduces the risk but doesn’t take it away completely. And it’s possible for anyone to get an STD. So you could be exposed without realizing it.

They’re scared to know the answer.

There’s a lot of stigma around STDs. People act like it’s a bad thing to have one, and there can be assumptions attached to an STD, such as the idea that it means someone is promiscuous. Maybe for these reasons, some people would rather stay in the dark. But these ideas are generally myths. You can get an STD from just one encounter, it’s possible get one in a loving relationship and they’re common to get. Overall, it’s best to know that you have an STD. It won’t go away by pretending it’s not there, and you could be spreading it to unsuspecting people, which isn’t something you would want done to you. There is treatment that can help, and without it, you may go through health complications that could be worse than having an STD.

The cost of testing holds them back.

You might have trouble affording the cost of testing, so you decide to skip it. But keep in mind that untreated STDs can end up progressing into other medical conditions, which could potentially cost you a lot more money in time. It’s one of those occasions where an ounce of prevention is worth a pound of cure. If you have a health insurance plan, it may cover STD testing. Also, there are affordable online STD tests you can do. If you really need to keep the cost down, consider testing for the type of STD(s) you think it’s most likely you could have come in contact with instead of testing for all of them. Individual STD tests can cost as little as the price of a new shirt, depending on the type of STD. Even a comprehensive test can be worth the cost for peace of mind and to ensure your state of health.

If one of these or another fear or barrier is holding you back from getting tested for STDs, think about whether you’re letting fear stand in the way of your health. STDs are common, so it doesn’t say anything bad about you if you have one. Ultimately, it’s best to know so it doesn’t progress, and there is treatment for STDs that can help you be healthier overall and have a healthy sex life going forward.