What’s the difference between an STI and an STD? - Play Safe
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STI stands for Sexually Transmitted Infection, not disease. That last word makes all the difference because most of the bacteria or viruses passed on via sex are actually infections, not diseases. Why? Because infections can be asymptomatic, but diseases can’t.

Asymptomatic means there are no symptoms – and most common STIs often show no symptoms at all. Diseases, however, all have symptoms. That’s why getting tested regularly is so important because a lot of the time you simply won’t know if you have an STI.

Another reason the medical community has moved away from the term STD is because of the stigma attached to the word ‘disease’. Most STIs are very easily treated or managed, so the term disease is a pretty big one for something that – medically at least – is often very minor.

Is chlamydia an STD or STI?

Chlamydia is an STI, not an STD. Because – you guessed it – it can have absolutely no symptoms whatsoever. Chlamydia is a super common infection in Australia with nearly 97,000 people diagnosed with it every single year. The good news is that it can be treated easily via antibiotics.

The same goes for syphilis and gonorrhea.

Another common STI is herpes. While herpes doesn’t have a cure like some other STIs, it’s also super common and can be managed with the right knowledge.

How do you know if someone has an STD or STI?

You can’t! So many STIs are asymptomatic, which means it’s impossible to tell if someone has one. In fact, a lot of people don’t even know themselves that they have an STI. If you’re concerned about STIs you should:

Talk to your partner

One of the best things that you can do to stay protected from STIs is to have open and transparent conversations with your partner about sexual health. Have they been diagnosed with any STIs recently? When did they last get an STI test? Have they had unprotected sex recently? Did they get tested afterwards? By having an honest conversation you’ll not only be safer but also feel more confident and comfortable.

Practice safe sex

Even after talking to your partner, it’s still not possible to be 100% sure if they have an STI or not. That’s why practicing safe sex – by using a condom and getting an STI test regularly – is so important. It’s the only way to keep yourself and your partner safe and protected. If you’re in a monogamous relationship and want to stop using condoms, it’s a good idea to both get tested first and have a talk about trust and boundaries.

What are 4 common symptoms of an STI?

As you know by now…if you do have an STI, it’s likely you won’t have any symptoms at all. However, if you do have symptoms they could include:

  1. Itching or redness in the genital area
  2. Pain when peeing or during sex
  3. Unusual discharge from the penis, vagina or rectum
  4. Unusual lumps and bumps

Here are specific symptoms of the more common STIs:


Chlamydia often doesn’t have symptoms, but can include vaginal discharge, pain when urinating or during sex, bleeding between periods. Or, if you have a penis; discharge, pain urinating, itching at the opening of the penis, or pain and swelling in the testicles. There are no symptoms in the throat. For anal sex, the symptoms can include anal discharge, bleeding.


Gonorrhea symptoms can include unusual vaginal discharge, pain or bleeding between periods or during sex. Symptoms in the penis almost always include yellow discharge, pain when urinating, and sometimes pain or swelling in the testicles as well.

There are no clear symptoms in the throat, but – if you’ve had unprotected anal sex – it could include anal discharge or bleeding.


If you do get symptoms during a syphilis infection, they might include ulcers in the mouth, penis, vagina or anus, or a red rash on the body – especially the palms of the hands and the soles of the feet. These symptoms could go away on their own but the infection is still in the body until you’ve been treated. It’s always safer to get tested.


The shame and stigma attached to this infection is completely undeserved, and lots of people have herpes but never know. If you do get herpes symptoms though, then these could include itching and tingling, followed by blisters that break and then heal on their own. If you notice any of these symptoms, it’s best to avoid sex until they’re gone.

Is an STI curable?

Good news people! Bacterial infections, including chlamydia, gonorrhea and syphilis, are all curable via a simple course of antibiotics. Trichomoniasis is another curable infection that’s fairly common in other parts of the world, but less common here in Australia. If you have been diagnosed with an infection that can’t be cured – such as herpes – please do not worry. Just like cold sores (oral herpes), the symptoms of genital herpes are usually more annoying than serious. It’s definitely still possible to have a healthy and safe sex life.

What should I do if I have STI symptoms?

If you notice any of the symptoms above, book yourself an STI test at your GP or nearest sexual health clinic. However – because most people won’t show any symptoms – it’s recommended that you get fully tested every 6-12 months, when you have unprotected sex, or when you change sexual partners.

By getting tested regularly and using condoms you know that you’re doing everything that you can to have a safe, healthy sex life.

Take the 30-second quiz: How to know if you have an STI.

If you have questions contact the NSW Sexual Health Infolink on 1800 451 624 between 9:00am and 5:30pm Monday to Friday to talk with a sexual health nurse. It’s confidential and free if you call from a landline.