Also called

  • STI


  • Anyone who is sexually active can catch an STI.
  • Correct use of condoms and dams can help reduce the risk of catching an STI.
  • Medical treatment can cure some STIs or help relieve symptoms for others
Sexually transmissible infections (STIs) are common all around the world. They may be caused by bacteria, viruses or parasites. You may think that only other people get STIs and that you are not at risk of catching one, but anybody who is sexually active can get an STI if they do not practice safe sex.

You can’t tell just by looking at a person that they have an STI. If you have unprotected sex with a person who has an STI, you are at high risk of catching that infection.

Sexually transmissible infections include chlamydia, herpes, gonorrhoea, syphilis, genital herpes, scabies, pubic lice (crabs), hepatitis and HIV (the virus that causes AIDS).

If you think you have been exposed to an STI, it’s a good idea to talk to your doctor or sexual health service about having a check-up, even if you do not have any signs or symptoms of an STI. Don’t try to diagnose your symptoms yourself, and remember that not all genital signs and symptoms are caused by an STI.

Symptoms of STIs

There are many different STIs and there are many signs that mean you may have caught one, but sometimes, there are no signs at all. When STIs do produce symptoms, they usually develop on the genital area. Your sexual contacts may also experience symptoms.

Generally, the symptoms of STIs can include:
  • unusual discharge from the penis, vagina or anus
  • pain during sex or urination
  • sores, blisters, ulcers, warts or rashes in the genital area
  • itchiness or irritation in the genital area
  • persistent diarrhoea
  • fever or flu-like symptoms
  • abnormal or unusual vaginal bleeding, especially after having sex
  • pain in the scrotum or testicles
  • lumps and bumps on the genitals.
Remember that many people who have an STI do not develop any symptoms and may not be aware they have an infection that can be passed on to their sexual partners, which is why check-ups are so important.

STIs are passed on during sex

The most common sexual activities that can spread an STI from one partner to another include:
  • vaginal sex – the man’s penis in the woman’s vagina
  • anal sex – the man’s penis in the partner’s anus (the partner can be either male or female)
  • oral sex – the man’s penis in the partner’s mouth, or the partner’s mouth or tongue in the woman’s vagina
  • oral-anal sex – one partner’s mouth or tongue on the other partner’s anus.

Diagnosis of STIs

The only way to find out if you have a sexually transmissible infection is to have a sexual health check-up. Doctors deal with sexual health problems on a daily basis, so don’t be embarrassed to ask for help.

Sexual health check-ups are easy to do. In most cases, it involves only a simple urine test. Some infections can be diagnosed on the day and treated at the time of your visit. Other results may take up to a week.

Testing for STIs

For people with no symptoms, testing for STIs depends on how sexually active you are and whether you use condoms consistently. It is recommended that you get tested:
  • after any unprotected sexual contact with a new or casual sexual partner
  • after any unprotected sex, if you know or suspect that your partner has had other sexual partners
  • after any unwanted or non-consensual sexual contact
  • after any unprotected sexual contact in countries where HIV and other STIs are common.
  • if your partner tells you that they have been diagnosed with a sexually transmitted infection.
If you are a gay man or a man who has sex with other men, it is important to get regular check-ups for STIs, including HIV and syphilis – at least every year. You should have more frequent (three-monthly) check-ups if you have a number of sexual partners.

How to reduce your risk of STIs

It is not difficult to avoid catching STIs. You can prevent most STIs by using barrier protection such as condoms, female condoms and dams (a thin piece of latex placed over the anal or vulval area during oral sex).

Most people are familiar with condoms for men. The female condom is a 14 cm, prelubricated sheath that fits loosely into the vagina and can be put in up to eight hours before sex. Female condoms should not be used together with male condoms because the friction between the two may cause the condoms to break.

Dams are rectangular sheets of latex that can be used to cover the vagina or anus to prevent the exchange of bodily fluids during oral sex. They are sometimes called dental dams because they are also used during dental surgery.

Condoms for men can be bought from supermarkets, pharmacists and other outlets. Female condoms and dams are available through Family Planning Victoria and may be available from selected shops. Latex-free condoms are also available from some outlets. Male condoms and lubricant are available free from the Melbourne Sexual Health Centre. Female condoms and dams are available on request. Female condoms are more expensive and not as widely available as condoms for men, but some couples prefer to use them.

Using condoms and dams

Condoms and dams are effective in helping prevent the spread of most STIs if they are used every time you have sex.

Some tips for correct use include:
  • Use well-known brands and check the expiry date.
  • Store in a cool, dry place away from direct sunlight.
  • Make sure the condom or dam is free of holes or breakage before use.
  • Use water-based lubricants such as KY. Don’t use Vaseline, baby oil or massage oils, which can weaken and split condoms or dams.
  • Use each condom or dam once only.
  • Use dams for oral sex only – do not use as protection for anal or vaginal sex.

Treatments for STIs

Many STIs are easily treated once they are diagnosed. Treatments for the different types of infections can include:
  • bacteria – (including chlamydia, gonorrhoea and syphilis) require treatment with antibiotics (either one high dose or a course)
  • parasites – (including pubic lice and scabies) require treatment with medicated shampoos
  • viruses – (including genital herpes, HIV, hepatitis B and human papillomavirus (HPV)) do not have a cure. In most cases, there are treatments to help control the symptoms.
If you have unprotected sex with a person who has an STI, you are at high risk of catching that infection. It is recommended that you talk to your doctor or sexual health service about having a check-up if you have had unsafe sex, even if you do not have any signs or symptoms of an STI.

Contacting sexual partners

Your sexual contacts may or may not experience signs and symptoms. If you have an STI it is important to contact any sexual partners you have had, so they can get tested and have treatment if necessary. This is an essential part of reducing the spread of STIs in our community.

Most people appreciate being told that they might have an STI, as often they are unaware of it. Your doctor or sexual health service can help you contact partners or it can be done anonymously via . This website can send an email or phone SMS informing a person that they have been a sexual contact of someone with a sexually transmissible infection.

Where to get help

  • Your doctor
  • Your school nurse or school welfare coordinator
  • Youth worker, welfare worker or social worker
  • Your local community health centre
  • Family Planning Victoria’s Action Centre (for people aged under 25 years) Tel. 1800 013 952 or (03) 9654 4766
  • Family Planning Victoria Tel. 1800 013 952 or (03) 9257 0100
  • Melbourne Sexual Health Centre Tel. (03) 9341 6200 or 1800 032 017 or TTY (for the hearing impaired) (03) 9347 8619
  • Victoria AIDS Council/Gay Men’s Health Centre Tel. (03) 9865 6700 or 1800 134 840
  • HIV, Hepatitis, STI Education & Resource Centre at The Alfred Tel. (03) 9076 6993
  • The Centre Clinic, Northcote Tel. (03) 9481 7155
  • The Centre Clinic, St Kilda Tel. (03) 9525 5866
  • Sexual Health Clinic Ballarat Tel. (03) 5338 4541
  • Bendigo Community Health Tel. (03) 5434 4300
  • Geelong Sexual Health Clinic Tel. (03) 5202 9333
  • STD Clinic Wodonga Tel. (02) 6022 8888 or 1800 657 573
  • STD/AIDS Clinic Traralgon Tel. (03) 5173 8111
  • HIV – Sexual Health Connect Tel. 1800 038 125

Things to remember

  • Anyone who is sexually active can catch an STI.
  • Correct use of condoms and dams can help reduce the risk of catching an STI.
  • Medical treatment can cure some STIs or help relieve symptoms for others

More information

Sexually transmitted infections

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Content Partner

This page has been produced in consultation with and approved by: Melbourne Sexual Health Centre

Last updated: July 2016

Content on this website is provided for education and information purposes only. Information about a therapy, service, product or treatment does not imply endorsement and is not intended to replace advice from your doctor or other registered health professional. Content has been prepared for Victorian residents and wider Australian audiences, and was accurate at the time of publication. Readers should note that, over time, currency and completeness of the information may change. All users are urged to always seek advice from a registered health care professional for diagnosis and answers to their medical questions.