Can you have more than one STI at once?

This is the part that catches people out. The World Health Organization says that more than 1 million curable STIs are acquired every day worldwide in people 15 to 49 years old, the majority of which are asymptomatic. It also notes that when symptoms do appear, they can be non-specific.

So if you have a positive result for one infection and feel fine otherwise, that is not much of a reassurance. You may well have had no symptoms from the first infection either. The other one could be just as quiet.

The reverse is true as well. If you have symptoms, such as burning when you pee, discharge or itching, they could come from one infection, from another, or from two at once. Looking at a symptom will not tell you which. Chlamydia and Gonorrhoea, for example, can feel very alike, as our post on how the two differ explains.

It does. Spain’s national surveillance report for 2025 had information on other infections for 1.0% of reported Gonorrhoea cases, and 59.6% of those also had Chlamydia. Because so few cases had this information, the figure does not show how common it is overall. It does show that the two turn up together.

Three things make a wider check sensible.

• The same kind of contact passes on many infections. Sex that carries a risk of one infection carries a risk of others. Condoms help a great deal, but they do not protect against infections that cause sores outside the genitals, such as Syphilis or genital Herpes, WHO notes.
• One infection can make another easier to catch. WHO says Herpes, Gonorrhoea and Syphilis can increase the risk of acquiring HIV.
• Your partner may have had more than one too. They may not know about either.

None of this says anything about you or your partner as people. A positive result for one infection, or for two, does not tell you who had it first, how long ago it arrived or whether anyone has been unfaithful. Some infections stay silent for a long time.

If you have had a positive result, or a partner has, the practical order is simple.

• Take the treatment you are given, and finish it. Chlamydia is usually treated with a course of antibiotic tablets, and Gonorrhoea with a single antibiotic injection, sometimes followed by tablets. Your partner or partners should be treated as well, and you should avoid sex until treatment is finished, otherwise the infection can pass back and forth.
• Check for the others. A single-infection test only answers one question. A screen answers several at once.
• Count from the right day. Tests work after the incubation period for that test. The count starts on the last day there was a risk, which is not always the encounter that is on your mind. If you test before the incubation period has passed, plan a second test once it has. This matters most for Syphilis: an early test picks up few infections, so a definitive negative result needs a later test.

Some screens need a blood sample and a urine sample, others only urine, so it helps to choose one that matches what you want to rule out. Our post on which STIs can be checked with a blood test sets this out.

Our Full Screen tests for Chlamydia, Gonorrhoea, Hepatitis B, HIV and the p24 Antigen, Mycoplasma, Syphilis and Ureaplasma. It uses a blood sample and a urine sample, has an incubation period of 28 days, and results are reported within 3 working days of your sample reaching the laboratory.

If you want the widest check, the Platinum Screen adds Gardnerella, Hepatitis C, Herpes 1 and 2 and Trichomonas. It also uses blood and urine samples, has a 28 day incubation period and the same 3 working day results time.

If your main concern is discomfort, itching or discharge, the Comfort Screen needs only a urine sample. It covers Chlamydia, Gardnerella, Gonorrhoea, Herpes, Mycoplasma, Trichomonas and Ureaplasma. The incubation period is 14 days and results come back within 2 working days of your sample reaching the laboratory.

Every screen is confidential. If anything is found, you can have a consultation and treatment through us, and our Patient Care Team is available 24/7 on 020 7099 0955.

The screens and results times above are for the UK. Not every country offers every screen, so if you are outside the UK, check the page for your country.

Believing you can only catch one STI at a time is one of several ideas that put people off testing. We tackle some of the others in five common myths about STIs and sexual health.

If you have just had one result and are wondering what else to check, that is exactly the right question, and one set of samples can answer it.

• World Health Organization. Sexually transmitted infections (STIs) fact sheet. https://www.who.int/news-room/fact-sheets/detail/sexually-transmitted-infections-%28stis%29
• Instituto de Salud Carlos III, Centro Nacional de Epidemiología. Vigilancia epidemiológica de las infecciones de transmisión sexual en España, 2025. October 2026. https://cne.isciii.es/documents/d/cne/vigilancia_its_2025

Medical review. This article was medically reviewed by Dr Steve Chapman, a doctor with a wealth of clinical experience in the field of STIs, on 2 November 2026. Better2Know content is reviewed for clinical accuracy before publication and updated when guidance or surveillance data changes. It is general information and not a substitute for personal medical advice.