What Are STIs? - A Guide to Infections, Symptoms & Testing

Sexually transmitted infections (STIs) are infections that are passed from one person to another through sexual contact. They’re extremely common – and many people with STIs don’t have symptoms. That’s why regular testing is so important.

This section is your starting point for understanding STIs, including what they are, how they spread, and what testing options are available. We’ll also explain why more experts now use the term “STI” instead of “STD.” If you’re new to sexual health or just looking for clear, no-judgment answers, you’re in the right place.

    Why it matters: Many STIs are easily treatable – but only if you know you have them. Learning the basics is the first step toward staying safe, getting tested, and protecting your health.
  

Understanding the basics of STIs helps break down the stigma and misinformation that often surround sexual health. While some people still use the term STD (sexually transmitted disease), most healthcare professionals now prefer “STI.” Why? Because many infections don’t cause disease, especially in the early stages – and calling them “infections” helps encourage testing before symptoms appear or long-term damage occurs.

Another key reason for shifting the language is to reduce fear. “Disease” can sound permanent or frightening, while “infection” implies that something can be diagnosed and treated. That linguistic shift makes it easier to talk about testing, safer sex, and health without judgment – especially for younger or first-time testers.

In this section, you’ll find articles that explain how STIs spread (hint: not just through intercourse), the symptoms to watch for (or the fact that many STIs are silent), and how to pick the right test. You’ll also find evidence-based answers to common questions like “Can STIs go away on their own?” or “Do you always need symptoms to test positive?”

Our goal is to make sure you’re informed, confident, and empowered to take control of your sexual health – whether that means testing after a new partner, getting screened as part of your routine, or seeking treatment discreetly if you test positive. Modern testing options are faster, easier, and more private than ever. So whatever your reason for exploring STI information, you’re already taking a smart step forward.

What Does STI Testing Look Like Today?

Today’s testing options are far more accessible than in the past. Many people choose discreet at-home test kits, which can be ordered online and completed in the privacy of your home. These kits typically involve a simple urine, swab, or finger-prick sample, and results are delivered securely online in just a few days. For others, walk-in labs or doctor’s offices remain a preferred choice – especially if symptoms are present or treatment may be needed the same day. Either way, STI testing has become faster, more private, and easier to fit into your schedule.

Who Should Get Tested?

Anyone who is sexually active should consider routine STI screening – especially those with new or multiple partners, people not using condoms consistently, or anyone whose partner’s STI status is unknown. The CDC recommends yearly screening for chlamydia and gonorrhea for sexually active women under 25, and more frequent testing for higher-risk groups. Even if you have no symptoms, testing is a smart move that helps protect you and your partners.

Explore Key Topics

Are STIs Curable?

Explore which infections are curable, which are treatable, and what that means for you.

How Do STIs Spread?

Understand the different ways STIs can be transmitted – including some you may not expect.

Symptoms of Common STIs

Recognize the signs – or lack thereof – of chlamydia, gonorrhea, herpes, and more.

STI vs STD: What’s the Difference?

Learn why the medical community now prefers “STI” and how it helps reduce stigma.

Can You Have an STI Without Symptoms?

Many STIs don’t cause symptoms. Here’s why testing matters – even when you feel fine.

What’s the Right STI Test for Me?

Get guidance on choosing the right testing based on your symptoms, exposure, or routine screening needs.

Do STIs Always Come From Sex?

Some STIs can spread through other types of contact. Get the facts.

Can STIs Go Away on Their Own?

Should you wait it out or take action? Find out what the science says.

Why Getting Tested for STIs Matters

Testing is the only reliable way to know your STI status and take charge of your health. Find out how and when to get tested.

Can You Prevent STIs Without Testing?

See how safer sex habits, vaccinations, and routine precautions can reduce your risk of STI transmission between tests.

Looking for Testing Options?

Whether you’re considering home kits or walk-in labs, STI testing today is more discreet and accessible than ever. Visit our Compare Tests page to explore your options or check our Where to Get Tested section to learn more.

If you’re unsure where to start, our guides walk you through the pros and cons of each option – including privacy features, turnaround times, and how to choose the right provider for your needs.