STIs and STDs aren’t the same thing. Really!

If you thought they were, you’re not the only one. The terms are often used interchangeably even though they’re different conditions.

So, what’s the diff and why does it matter? We’ll get to that and answer some of your other STI and STD questions here.

STIs are sexually transmitted infections. STDs are sexually transmitted diseases.

An STI is only considered a disease when it causes symptoms. That’s it. That’s the one difference.

Why the switch after years of referring to all sexually transmitted ailments as STDs? To improve accuracy and stigma.

STI is more accurate for most cases. Also, STD is an acronym that causes some people to shudder thanks to years of subpar sex ed and bad after-school specials.

Think of an infection as the first step on the road to disease. Infections haven’t yet turned into disease and often don’t cause any symptoms.

This is actually why many experts are pushing to use STI over STD, and believe “STD” is misleading.

“Disease” suggests that a person has a medical problem with obvious signs and symptoms. That’s often not the case at all since the most common STIs — like chlamydia and gonorrhea — are often asymptomatic.

Not all diseases start as infections, but when it comes to sexually transmitted ones, they do.

Infections occur when pathogens like viruses, bacteria, or parasites enter your body and start to multiply. How they get into your body depends on the type of pathogen.

Some get in through skin-to-skin contact with a person who has an infection; others are transmitted through an exchange of bodily fluids, like semen, vaginal secretions, or blood.

Infection progresses to disease when these pathogens cause damage to your cells, and signs and symptoms appear.

Some STIs never develop into STDs. Take HPV, for example.

HPV usually clears up on its own without causing any health problems. In these cases, HPV is an STI.

If the infection doesn’t clear on its own, it can cause genital warts or certain cancers. This then makes it a disease.

Symptoms can take days, weeks, or even years to appear, if they do at all, which is why testing is important. (More on that in a sec.)

That said, anyone who’s sexually active should know what symptoms to watch out for.

Keep in mind that symptoms vary between STDs and can affect different parts of your body, depending on the type of sexual activity you’ve had.

For the record, this goes for any types of sexual activity, including vaginal and anal sex, oral (rimming, too!), hand jobs/hand sex, dry humping, etc., etc., etc.

Here’s what to look out for:

  • bumps, sores, or rashes in or around the genitals, anus, buttocks, or thighs
  • changes in the amount of, color, or smell of vaginal discharge
  • penile discharge
  • unusual vaginal bleeding or spotting between periods or after sex
  • painful or burning urination
  • pain during vaginal or anal penetration
  • pelvic pain
  • painful or swollen testicles
  • tingling or itching around the genitals
  • swollen and painful lymph nodes, especially in the groin and neck
  • genital or anal rash
  • rectal bleeding

The Centers for Disease Control and Prevention (CDC) recommends yearly screening for all sexually active adults, but a good general rule of thumb is to get tested if you:

  • have had sex without a barrier method, like a condom
  • have had or are planning to have sex with a new partner
  • have multiple sexual partners
  • are worried you may have been exposed to an STI
  • are pregnant
  • share injection drug equipment

But don’t jump straight from the sack to the screening clinic, because getting tested too soon won’t tell you whether you were exposed to an STI from your most recent sexual encounter.

STIs have an incubation period. That’s the time between when you contract the infection and your body recognizes and produces antibodies to it.

The presence of these antibodies — or lack thereof — is what gives you the result.

Incubation periods vary between infections, from a few days for chlamydia and gonorrhea to months or years for HPV and syphilis.

That said, if you have reason to believe you’ve been exposed to an STI, talk to a healthcare provider for advice as soon as possible.

Depending on your situation, they can advise you on the next steps, like when to get tested or about preventive measures, such as post-exposure prophylaxis (PEP) if you may have been exposed to HIV.

That depends on your results.

Negative result

If you receive a negative result, stay on top of screening with regular STI testing.

Ask your healthcare provider about the best screening schedule for you based on your individual risk factors. You can also talk to them about the best ways to reduce your risk for STIs, like using barrier methods or PrEP.

Positive result

If you receive a positive result, your healthcare provider will prescribe a treatment or management plan depending on the diagnosis.

You’ll also need to notify your partner(s) so they can be tested and treated if needed. Not sure how to tell them? We’ve got you! This guide can help.

The most common STIs are caused by bacteria. A course of antibiotics can usually cure them.

Antibiotics don’t work on infections caused by viruses. Some viral infections clear on their own, but most are long-term conditions. Antiviral medications can usually manage symptoms and reduce the risk of transmission.

For STIs like crabs, which are caused by something other than bacteria or viruses, topical and oral medications usually do the trick.

Retesting might be recommended to make sure the treatment has worked.

Even though STIs and STDs are technically different, chances are you’ll continue to see the acronym used interchangeably. No biggie, because now you know what’s what.

Bask in the feeling of knowing the difference, and continue to stay on top of your sexual health. Knowledge is power, friends!

Adrienne Santos-Longhurst is a Canada-based freelance writer and author who has written extensively on all things health and lifestyle for more than a decade. When she’s not holed-up in her writing shed researching an article or off interviewing health professionals, she can be found frolicking around her beach town with husband and dogs in tow or splashing about the lake trying to master the stand-up paddle board.