The 3 most common STIs/STDs

The test looks for three organisms, each linked to a different infection:

• Chlamydia trachomatis, the bacterium behind chlamydia. It is often silent, especially in women, and when it does cause symptoms, they tend to be burning when you pee, unusual discharge or pain in the lower belly or testicles.
• Neisseria gonorrhoeae, the bacterium behind gonorrhoea. Men are more likely to notice it, usually as burning or discharge within a few days, while in women it frequently goes unnoticed.
• Trichomonas vaginalis, the parasite behind trichomoniasis, often shortened to trich. Most people have no symptoms, and women are more likely than men to notice a change in discharge, itching or soreness.

All three are passed on through sex and all three are treatable, which makes finding them the important part.

Chlamydia, gonorrhoea and trichomoniasis travel the same routes, and when they do cause symptoms, those symptoms look alike. Burning, discharge or irritation could come from any of them, and sometimes from two at the same time. Testing for one and not the others leaves the picture half finished.

A combined PCR test answers all three questions from a single sample. If everything is negative, you have three clear answers instead of one. If something is positive, your doctor knows exactly which infection to treat, which matters because chlamydia and gonorrhoea are treated with antibiotics and trichomoniasis with a different medication.

This test makes sense if you have a new partner, more than one partner, or sex without a condom, and you want a clear answer about these three infections. It is also useful if a partner has told you they tested positive, or if you have noticed burning when you pee, a discharge that isn't your usual, or irritation in the genital area.

Many people choose it as a regular check between partners, with no symptoms at all, precisely because these infections so often have none. If you have had oral or anal sex, tell us when you order, because a swab from the throat or anus is needed to check those areas.

If you want a wider check that includes HIV, syphilis or herpes, those infections need other tests. You can see exactly what each test includes before you buy it.

For a reliable result, test around 10 days after the contact you want to check. PCR is very sensitive, but an infection needs a little time to build up to a level the test can find, and testing straight after sex can give a negative simply because it was too soon.

If you give a urine sample, don't pee for at least two hours beforehand, then collect the first part of your pee, the first 10 to 20 mL, in a sterile container. The first part carries the most material from the urethra, which is where the test looks. If you give a swab, the laboratory will explain how it is taken.

If you have symptoms or a partner has tested positive, speak to a doctor without waiting for the 10 days. They may treat you straight away and confirm with a test afterwards.

A result is only as good as the lab behind it, and we chose ours the way you'd choose anyone you let that close.

Your report shows a result for each of the three organisms, positive or negative. A positive result means the infection was found and can now be treated. Take your report to a doctor, who will prescribe the right medication and advise on telling recent partners, so the infection isn't passed back and forth.

A negative result means none of the three were found in your sample. It is most reliable when you tested around 10 days after your last contact and gave the right sample for the kind of sex you have had. If you tested very early, or your symptoms continue, test again later or see a doctor.

You buy the test online, then go to a partner laboratory in Barcelona, Valencia, Madrid or Málaga, without a GP referral. In Barcelona and Madrid you go during collection hours, and in Valencia and Málaga with an appointment. The laboratory takes your sample, runs the analysis and sends your results, usually in about two days.

You wouldn't pick the cheapest surgeon, the cheapest parachute or the cheapest tattoo artist, and we chose the lab that reads your sample with exactly the same logic.

Can I test for chlamydia, gonorrhoea and trichomoniasis with no symptoms?

Yes. All three are often present without symptoms, so testing after a new partner or sex without a condom is the only way to know. Many people test regularly for exactly this reason.

How long after sex should I take an STI test?

Around 10 days after the contact you want to check. Testing earlier can give a negative result because the infection has not yet reached a level the test can detect.

Is a urine test enough for chlamydia and gonorrhoea?

For genital infections, yes. Urine does not check the throat or rectum, so if you have had oral or anal sex, a swab from that area is needed. Tell us when you order and we will add the right swab.

What is the difference between urine and a swab?

Urine is the simplest sample for infections in the genital area. A swab collects material directly from a specific area, such as the vagina, urethra, throat or anus, and is the right choice when you want to check an area that urine cannot reach.

How long do results take?

Your results are usually ready in about two days.

What happens if my result is positive?

See a doctor with your report. Chlamydia and gonorrhoea are treated with antibiotics and trichomoniasis with a short course of a different medication. It's a good idea for your recent partners to test and get treated too, and your doctor will tell you when it is safe to have sex again.

This information does not replace medical advice. Discuss your results and any next steps with your doctor.

Can I take this test while I'm on antibiotics?

Keep taking your usual medication. You can't take this test while you're on antibiotics: ask your doctor when to take it.