An STI in your mouth or throat usually causes no symptoms. In a cohort of men who have sex with men, 92 percent of throat infections with gonorrhoea ran their course with no symptoms at all (Morris, 2006). So you can have a throat STI, pass it on, and feel nothing.
That makes this topic trickier than an ordinary sore throat. With a cold, you know within a week what it was. With a throat STI, silence is the most common sign.
We are a testing provider, so let us say up front how it works: a normal STI test from urine or blood does not look in your throat. That needs a separate swab. On this page you will read which STIs can sit in the mouth or throat, how to recognise them, how transmission works, and what a test can and cannot find here.
Can you get an STI in your throat or mouth?
Yes. During unprotected oral sex, the bacteria and viruses that cause STIs can land on the lining of your throat or mouth. For some STIs the throat is even a suitable place to survive, without you noticing anything. A throat STI is also called an oral or oropharyngeal STI.
The mouth and the throat are not the same story. In the throat, behind your tonsils, gonorrhoea and chlamydia settle in particular. In and around the lips and mouth, herpes and sometimes syphilis play out, through sores or blisters.
It is almost always oral sex as the route of transmission. With gonorrhoea, kissing also seems to play a role, something we cover separately below.
Which STIs can you get in your throat?
The STIs that can sit in the throat or mouth are mainly gonorrhoea and chlamydia, and alongside them syphilis, herpes (HSV) and, to a lesser extent, HIV. Not every STI behaves the same in this spot: some cause a throat infection, others a sore or blister, and still others a normal STI test will not find here at all.
The table below sets them side by side. Look at that last column: it tells you what our test does and does not do here.
| STI | Can it sit in the throat/mouth? | What you might notice | How you test for it | In our CGT test? |
|---|---|---|---|---|
| Gonorrhoea | Yes, often (throat) | Usually nothing, sometimes a sore or red throat | Throat swab (PCR) | Yes, but with a throat swab |
| Chlamydia | Yes, less often (throat) | Almost always nothing | Throat swab (PCR) | Yes, but with a throat swab |
| Syphilis | Yes (sore in the mouth) | A painless sore on lip, tongue or in the mouth | Blood test | No, separate test |
| Herpes (HSV-1) | Yes (cold sore) | Blisters or a cold sore on or around the lip | Swab of a blister | No, separate test |
| HIV | Rarely via the mouth | Nothing in the mouth itself | Blood test | No, separate test |
Two things stand out. First, most throat STIs give little or nothing away. Second, only the throat part of gonorrhoea and chlamydia sits in a throat swab; syphilis, herpes and HIV need a different test. So anyone who only has blood or urine taken looks straight past a throat infection.
How does a throat STI feel?
Usually you feel nothing. That is not reassurance, it is the hard part. Research into throat gonorrhoea shows the large majority runs without symptoms (Morris, 2006), and a broader review found the same picture for most throat and rectal infections with chlamydia and gonorrhoea (Chan, 2016).
When there is something to notice, it is vague.
Think of a throat that feels a bit raw or irritated, mild pain when swallowing, a red throat, or swollen glands. Exactly the complaints that come with an ordinary throat infection too. That is why the feeling in your throat is a poor guide: it does not point you to the cause. More on that distinction is in our article on a sore throat from an STI or a throat infection.
Herpes is the exception you do see: a cold sore or blisters on the lip are visible and often tender. But herpes on the mouth works differently from throat gonorrhoea, and we do not mix them up on this page.
How do you tell a throat STI from an ordinary throat infection?
From the complaints alone, you cannot. A throat STI and an ordinary throat infection can look exactly the same, and both sometimes give a red throat or pain when swallowing. The difference is not in what you feel, but in what happened around it: was there unprotected oral contact, and with whom.
An ordinary throat infection comes from airborne viruses or bacteria and often clears on its own. A throat gonorrhoea does not clear by itself and stays contagious until it is treated.
The practical rule of thumb: complaints that fit a cold, without recent unprotected oral contact, rarely point to an STI. If unprotected oral sex with a new or changing partner was involved, the throat is a spot a normal test misses. You only get certainty with a throat swab, not by looking or feeling.
Can you pass a throat STI on?
Yes. A throat infection can move to a partner's genitals during oral sex, and the other way around. Precisely because a throat STI usually gives no symptoms, that passing on often happens without anyone knowing. That is one reason the throat is seen as a silent source.
With gonorrhoea there is something extra. A large study of men in Melbourne found that kissing, even without sex, was linked to throat gonorrhoea (Chow, 2019). The evidence is not settled, but it shows the throat has more routes than oral sex alone.
We work that out in can you get an STI from kissing. For chlamydia, HIV and most other STIs, kissing is not a known route; for herpes and syphilis, a sore or cold sore in the mouth can be.
How do you test for an STI in the mouth or throat?
With a swab of the throat, not with urine or blood alone. For gonorrhoea and chlamydia in the throat, a swab is taken along the back of your throat and then examined with a PCR. That method is more sensitive than a culture and is the standard for the throat (Chan, 2016).
The key point: a urine test or blood test says nothing about your throat.
If your complaint or your risk sits in the throat, you need a throat swab, separate from the genital test. A reassuring detail for anyone testing at home: a throat swab you take yourself has proven in research to be almost as reliable as one taken in a clinic, with accuracy above 99 percent (Orser, 2024). How such a swab works exactly is in testing for a throat STI: how a throat swab works.
Our test for chlamydia, gonorrhoea and trichomonas shows those infections with a PCR. If you want your throat checked specifically, choose a throat swab when ordering, because the standard sample looks at the genital side.
When does a throat STI give symptoms?
Sometimes you do notice something, and then it is usually mild and non-specific. With throat gonorrhoea the throat can feel raw or red, the tonsils can be swollen, and there is sometimes some coating at the back. With chlamydia in the throat there is almost never anything to notice. On their own, these complaints say little about the cause.
What you should not do is read the absence of symptoms as proof that there is nothing.
Because silence is the rule here, not feeling anything is no all-clear. We work that out further in can you have a throat STI without noticing. And if your complaint is a persistent sore throat, chlamydia in the throat takes you further into what that one infection actually does.
Two people with the same raw throat
Picture two people waking up on a Monday morning with exactly the same complaint: a raw, slightly red throat, mild pain when swallowing. No fever, nothing else. For both it feels like a cold coming on.
For the first, it started after a weekend of too little sleep and a housemate with a cold. No unprotected contact in months. For them the chance of a throat STI is close to zero, and a test would confirm that neatly without saying anything new. The throat heals on its own.
For the second, it also started out of nowhere, but there was unprotected oral sex with someone new ten days earlier. Same throat, completely different question. For them a normal urine test looks past the spot where the risk sat, and only a throat swab gives an answer.
The difference was never in the throat itself.
It sat in what happened around it. That is why we do not use symptom checklists or photos to help you choose: two identical throats can need two completely different answers, and only you know what else was going on.
How common is a throat STI?
Exact figures for the whole population do not exist, because far from everyone is tested on the throat. In groups that are tested there routinely, it turns out to be no rarity: in the study mentioned earlier, 5.5 percent of the men tested had throat gonorrhoea (Morris, 2006), and a cross-sectional study found that all the extragenital infections it detected ran without symptoms (Calas, 2021).
In the Netherlands, the RIVM tracks STI figures through the sexual health centres, where people from at-risk groups can get tested for free. According to the RIVM, gonorrhoea and syphilis remain stably high there. That the throat is sometimes included separately in those tests is precisely because an infection there stays unnoticed so easily.
Herpes is a different matter. According to the WHO, an estimated 3.8 billion people under 50 (64 percent) carry herpes simplex virus type 1, which spreads mainly through mouth-to-mouth contact and can sometimes cause genital herpes through oral sex. A cold sore is therefore extremely common, and by no means always something to worry about.
Further reading in this cluster
We work out the separate pieces in individual articles. Go to a sore throat from an STI or throat infection if a sore throat is your main complaint, or to chlamydia in the throat for that one infection.
If you want to know how transmission works, read can you get an STI from kissing. And for the practical side: how a throat swab works and a throat STI without symptoms.
If your complaint fits the general list better, STI symptoms in men and women gives the wider overview, and which STI test you need when helps you choose.
References
- Morris SR, et al. Prevalence and incidence of pharyngeal gonorrhea in a longitudinal sample of men who have sex with men: the EXPLORE study. Clinical Infectious Diseases, 2006. PMID 17051493.
- Chan PA, et al. Extragenital Infections Caused by Chlamydia trachomatis and Neisseria gonorrhoeae: A Review of the Literature. Infectious Diseases in Obstetrics and Gynecology, 2016. PMID 27366021.
- Calas A, et al. Prevalence of urogenital, anal, and pharyngeal infections with Chlamydia trachomatis, Neisseria gonorrhoeae, and Mycoplasma genitalium: a cross-sectional study in Reunion island. BMC Infectious Diseases, 2021. PMID 33478403.
- Chow EPF, et al. Kissing may be an important and neglected risk factor for oropharyngeal gonorrhoea: a cross-sectional study in men who have sex with men. Sexually Transmitted Infections, 2019. PMID 31073095.
- Orser L, et al. Testing for extragenital Neisseria gonorrhoeae and Chlamydia trachomatis: At-home pharyngeal and rectal self-swabs are non-inferior to those completed in healthcare settings. PLoS One, 2024. PMID 38768150.
- World Health Organization (WHO), Herpes simplex virus, fact sheet. Accessed July 2026.
- RIVM, STI surveillance Netherlands. Accessed July 2026.
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