Do I have an oral STI? Symptoms and testing

Yes. Oral sex can pass on:

• Gonorrhoea and Chlamydia, which spread through semen and vaginal fluid and can infect the throat
• Herpes, including from a cold sore to the genitals. The cold sore virus is now the most common cause of genital Herpes in the UK.
• Syphilis, through contact with a sore on the genitals or in the mouth
• HPV, which can affect the mouth and throat

Infections can pass both ways: from genitals to throat when you give oral sex, and from mouth to genitals when you receive it. The risk of HIV from oral sex is very low, estimated at less than 1 in 10,000. Read more in “Can you get HIV from oral sex?”

Most throat infections cause no symptoms, so you can have one without knowing. When there are signs, they depend on the infection:

• Gonorrhoea and Chlamydia in the throat: usually none, but sometimes a sore throat
• Herpes: cold sores, which start with a tingling, itching or burning feeling, followed by painful blisters on or around the lips
• Syphilis: a sore in the mouth or on the lips, which is usually painless, and later white patches in the mouth
• HPV: usually no symptoms
• HIV: some people get a short flu-like illness, which can include a sore throat, 2 to 6 weeks after infection

Sore throats and tonsillitis are usually caused by viruses such as a cold or flu, so a sore throat on its own doesn’t mean you have an STI. Read more in “What does an oral Chlamydia infection look like?”

Because throat Gonorrhoea rarely causes symptoms, it often isn’t found unless you’re tested. It’s also harder to treat than Gonorrhoea in the genitals.

The throat is where antibiotic resistance is most likely to develop. Gonorrhoea can pick up resistance genes from harmless bacteria that live in the throat, and 3 of the 4 confirmed cases in England where treatment failed were in the throat. That’s why UK guidelines recommend a follow-up test for everyone treated for throat Gonorrhoea. Read more in “Can Gonorrhoea infect the mouth?”

Yes. If you have Gonorrhoea or Chlamydia in your throat, you can pass it on to a partner through oral sex, and a cold sore can give a partner genital Herpes.

Untreated genital infections can cause serious problems, including pelvic inflammatory disease, which can lead to infertility or ectopic pregnancy, and infection in the testicles.

Each infection needs the right sample:

• Gonorrhoea and Chlamydia in the throat: a throat swab. A urine test only checks your genitals.
• Herpes: a swab from a sore, if you have one.
• Syphilis and HIV: a blood test.

UK guidelines recommend throat testing for gay and bisexual men, sex workers, partners of people with Gonorrhoea, and anyone with Gonorrhoea in the genitals. For everyone else, it depends on the kind of sex you’ve had. You can take a throat swab yourself: UK guidelines say self-taken swabs work well. Read more in “How to take a swab sample for a home test”

• Use a condom on the penis, or a dam, a thin square of latex or plastic, over the vagina, for oral sex.
• Don’t give or receive oral sex if either of you has a cold sore, from the first tingle until it has fully healed, or any other sores.
• Get tested regularly, and include a throat swab if you have oral sex.
• Get vaccinated if you’re offered it. The HPV vaccine protects against the types of HPV linked to some mouth and throat cancers. Since August 2025, some gay and bisexual men at higher risk in England have been offered a vaccine that gives around 30% to 40% protection against Gonorrhoea.

Read more in “How long after a cold sore can you give oral sex?”

Better2Know offers:

• Oral Screen: a home test kit that checks a throat swab and a urine sample for Chlamydia and Gonorrhoea, and a finger-prick blood sample for Herpes 1, Herpes 2 and Syphilis. You can take it from 14 days after sex (28 days for Herpes), with results in 2 days.
• Herpes Simplex Type 1 and 2 (Swab): if you have a sore, a swab from it checks for Herpes 1 and Herpes 2, with results in 5 days.
• HIV 4th Generation: a blood test for HIV from 28 days after sex, with results in 1 day. You can book it at one of our clinics or order a home test kit.

If you test before 45 days, a negative HIV result needs a repeat test. A Syphilis test in the first 3 months after sex can miss the infection, so you may need a repeat test. Not sure which test you need? Our Patient Care Team is available 24/7 on 020 7099 0955.

Is oral sex safer than vaginal or anal sex?

For HIV, yes: the risk from oral sex is very low. But Gonorrhoea, Chlamydia, Herpes, Syphilis and HPV can all pass on through oral sex, so it isn’t risk free. Read more in “I had unprotected oral sex. Should I get tested?”

Can you get an oral STI from kissing?

Cold sores and Syphilis sores can spread through kissing. Chlamydia isn’t known to spread that way. Read more in “Can you get Chlamydia from kissing?”

Can oral sex cause throat cancer?

Some types of HPV, which can pass on through oral sex, are linked to a type of throat cancer. Most HPV infections clear up on their own within 2 years. Read more in “Michael Douglas and HPV: the link between oral sex and throat cancer”

Oral sex carries a very low risk of HIV, but it can pass on several other STIs, and infections in the throat usually cause no symptoms. If you have oral sex with new or casual partners, a test that includes a throat swab is the only way to know.

Order an Oral Screen home test kit. Our Patient Care Team is available 24/7 on 020 7099 0955.

Not in the UK? Choose your country from the selector at the top of the page for local tests and prices.

This article originally appeared on 15 February 2019 and was last updated on 1 October 2026.

This article is general information and not a substitute for personal medical advice.

Sources

1. NHS, Gonorrhoea, reviewed 16 December 2024. https://www.nhs.uk/conditions/gonorrhoea/
2. NHS, Chlamydia, reviewed 24 October 2024. https://www.nhs.uk/conditions/chlamydia/
3. NHS, Syphilis, reviewed 17 March 2026. https://www.nhs.uk/conditions/syphilis/
4. NHS, Genital herpes, reviewed 27 June 2023. https://www.nhs.uk/conditions/genital-herpes/
5. NHS, Cold sores, reviewed 19 February 2024. https://www.nhs.uk/conditions/cold-sores/
6. NHS, Human papillomavirus (HPV), reviewed 10 March 2026. https://www.nhs.uk/conditions/human-papilloma-virus-hpv/
7. NHS, HIV and AIDS, reviewed 9 July 2025. https://www.nhs.uk/conditions/hiv-and-aids/
8. NHS, Tonsillitis, reviewed 8 March 2024. https://www.nhs.uk/conditions/tonsillitis/
9. NHS, Sore throat, reviewed 8 April 2024. https://www.nhs.uk/conditions/sore-throat/
10. NHS, HPV vaccine, reviewed 1 September 2023. https://www.nhs.uk/vaccinations/hpv-vaccine/
11. NHS, MenB vaccine for gonorrhoea, reviewed 28 August 2025. https://www.nhs.uk/vaccinations/menb-vaccine-for-gonorrhoea/
12. British Association for Sexual Health and HIV, UK national guideline for the management of infection with Neisseria gonorrhoeae, 2025. https://www.bashh.org/_userfiles/pages/files/fiferetal2025britishassociationofsexualhealthandhivuknationalguidelineforthemanagementofinfection_1.pdf
13. British Association for Sexual Health and HIV, UK national guideline for the management of infection with Chlamydia trachomatis, 2026. https://www.bashh.org/_userfiles/pages/files/national_guideline_for_the_management_of_infection_chlamydia_trachomatis_2026.pdf
14. British Association for Sexual Health and HIV, UK national guideline for the management of anogenital herpes, 2024. https://www.bashh.org/_userfiles/pages/files/pateletal2024britishassociationofsexualhealthandhivuknationalguidelineforthemanagementofanogenital.pdf
15. British Association for Sexual Health and HIV, UK guidelines for the management of syphilis, 2024. https://www.bashh.org/_userfiles/pages/files/syphilis_2024.pdf
16. British HIV Association and British Association for Sexual Health and HIV, UK guideline for the use of HIV post-exposure prophylaxis, 2021, amended 2023. https://bhiva.org/wp-content/uploads/2024/10/PEP-guidelines.pdf
17. British HIV Association, British Association for Sexual Health and HIV and British Infection Association, Adult HIV testing guidelines, 2020. https://bhiva.org/wp-content/uploads/2024/10/HIV-testing-guidelines-2020.pdf
18. UK Health Security Agency, GRASP report: data to September 2025, updated 18 December 2025. https://www.gov.uk/government/publications/gonococcal-resistance-to-antimicrobials-surveillance-programme-grasp-report/grasp-report-data-to-september-2025
19. Lewis DA. Will targeting oropharyngeal gonorrhoea delay the further emergence of drug-resistant Neisseria gonorrhoeae strains? Sexually Transmitted Infections, 2015;91(4):234. https://sti.bmj.com/content/91/4/234
20. Cancer Research UK, Does HPV cause cancer?, reviewed 24 January 2024. https://www.cancerresearchuk.org/about-cancer/causes-of-cancer/infections-hpv-and-cancer/hpv-and-cancer