Can You Get an STD from Kissing?
When it comes to sexual health, many people wonder: can simply kissing someone give you a sexually transmitted infection (STI), often called a sexually transmitted disease (STD)? The short answer is: yes—but the risk is generally low, and depends on several factors. In this post we’ll cover which STIs can be transmitted via kissing, which ones usually can’t, what increases or decreases the risk, symptoms, prevention, and when to talk to a healthcare provider.
Don’t Wait for Symptoms
Early testing is the safest step. Protect yourself and your partners.
What we mean by “kissing”
First: not all types of kissing carry the same risk. Broadly, there are two types:
- Dry or closed-lips kissing (no tongue contact), small amounts of saliva exchanged
- Deep/fluid-exchange kissing (“French kissing” or kissing with tongue), with more saliva exchange and more mucous membrane contact
The risk of transmitting an STI is higher in the second scenario, especially if there are open sores or breaks in the mouth or on the lips, or if one partner is having an active outbreak of some infection.
STIs that can be transmitted by kissing
Here are STIs for which there is evidence (or at least plausible biological mechanism) that kissing may lead to transmission.
| Infection | How transmission through kissing might happen / what increases risk |
|---|---|
| Oral Herpes (HSV-1, less often HSV-2) | HSV-1 is the classic “cold sore” virus. It lives in and on the mucous membranes around the mouth. Kissing someone with a cold sore (or even just before a visible sore appears) can spread HSV-1. |
| Syphilis | Syphilis causes sores (“chancres”) that can appear in the mouth or on the lips. If someone has an active syphilis sore in or around the mouth, kissing can transmit bacteria if there’s direct contact. |
| Cytomegalovirus (CMV) | CMV is a virus that can reside in saliva, and can be transmitted via saliva exchange. While many people live with CMV asymptomatically, it’s more concerning in people with weakened immune systems. |
| Human Papillomavirus (HPV) | Some evidence suggests that certain strains of HPV can be transmitted through mouth-to-mouth contact (especially if there are micro abrasions or mucous membrane contact). HPV in the mouth/throat can in some cases lead to oropharyngeal cancer. |
| Gonorrhea | Recent studies suggest that oropharyngeal gonorrhea (infection of the throat) can be associated with kissing, especially deep kissing, potentially as a risk factor. However, the risk is much lower than from oral/genital or anal sexual contact. |
| Epstein-Barr Virus (EBV) | Although EBV isn’t traditionally grouped with “STIs,” it is a virus that is very commonly transmitted via saliva and kissing. It causes mononucleosis (“mono”). It’s not usually thought of as an STD, but it’s relevant when considering what you can get from saliva exchange. |
STIs that don’t (or very rarely) spread through kissing
Many STIs are not passed via saliva or simple kissing. Here are some that typically are not transmitted through kissing:
- Chlamydia – requires genital contact or oral-genital contact; saliva is not thought to be a route.
- HIV – although HIV can be transmitted via blood, sexual fluids, etc., saliva alone is normally insufficient to transmit the virus. There would need to be blood, open sores, etc. The risk via kissing is extremely low to negligible.
- Trichomoniasis – parasitic infections requiring genital contact; saliva or mouth-to-mouth contact is not a known route.
- Hepatitis B & C – Normally transmitted via blood, sexual fluids, etc. Not typically spread through casual kissing; though open sores or cuts could theoretically increase risk for some. But general consensus is that kissing is not a route for most hepatitis viruses.
What factors increase risk when kissing
Even for those STIs that can be transmitted via kissing, several conditions make transmission more likely:
- Active lesions or sores – cold sores, syphilitic chancres, or any breaks in skin or mucous membrane (e.g. cuts, ulcers, inflamed gums). These provide direct entry points.
- Saliva exchange and wetness – the more saliva exchanged, the higher the chance of infection, especially with viruses that live in saliva or mucous membranes. Deep, wet kissing is riskier than light or closed-mouth kisses.
- Oral health – gum disease, bleeding gums, recent dental work, or other oral wounds raise risk because they allow easier entry of pathogens.
- Immune status – people with weakened immune systems are more susceptible to more severe disease or being more easily infected.
- Concurrent sexual activity – if one or both partners are engaging in oral or genital sexual activity (or both), the risk pool increases. Some infections acquired orally can be transmitted genitally, and vice versa.
What are the symptoms to watch for?
Because many infections transmitted via kissing can be asymptomatic (show no symptoms), it’s essential to know what to look for. If you’ve kissed someone and are concerned, here are possible signs:
- Cold sores or blisters — on or around lips or inside the mouth (HSV)
- Sores or ulcers in the mouth, throat, or on lips — especially painless ones (syphilis)
- Sore throat, red/swollen tonsils, maybe white patches or spots in the mouth or throat (could be gonorrhea or some viral infections)
- Swollen lymph nodes in the neck
- Fever, body aches, fatigue — especially with viral infections (like CMV or EBV)
- Oral warts or growths (HPV)
If you notice unusual symptoms, particularly ulcers/sores, swelling, or pain that last more than a few days, it’s wise to see a healthcare provider.
How likely is transmission? How dangerous?
It’s important to keep perspective.
- Overall, kissing is considered low risk compared to activities like oral, anal, or vaginal sex.
- Many people have had HSV-1 by adulthood — it’s very common. Some estimates place it around 50-70% in certain populations.
- Even when infection is possible, many infections are mild or go unnoticed. Others can be more serious, especially when untreated in the case of bacterial STIs like syphilis or gonorrhea.
Prevention: reducing your risk
Because even low risk doesn’t mean no risk, here are ways to reduce the chance of catching an STI from kissing.
- Avoid kissing when you or your partner have visible sores, cold sores, or open wounds around the mouth.
- Maintain good oral hygiene. Treat gum disease, avoid bleeding gums, take care of mouth wounds.
- Limit number of partners or know the STI status of your partner(s). Honest communication is key.
- Avoid deep, wet kissing if you are concerned about risk — or at least understand the risk.
- Use barrier methods during oral sex (condoms, dental dams) when possible, because often kissing is part of broader sexual activity.
- Regular STI screening/sexual health check-ups. Even when no symptoms.
When to see a healthcare provider
If you believe you’ve been exposed, or if you have symptoms, it’s important to reach out for professional help. Some things to do:
- If you notice any sores or ulcers in mouth or lips, especially if painless or accompanied by other symptoms (fever, swollen glands) → get tested.
- If you have a partner who has tested positive for an STI, even if you have no symptoms, ask your doctor about screening.
- If you engage in sexual activity with new partners or multiple partners, regular checkups are wise.
Bottom line
Yes, you can get certain STIs from kissing—but the risk is generally low unless certain risk factors are present (open sores, saliva exchange, poor oral health). Understanding what those STIs are, staying informed, practicing good oral hygiene, and communicating with partners can help keep you safe.
FAQ
Q: Can HIV be transmitted through kissing?
A: Very unlikely. HIV is not transmitted via saliva under normal circumstances. Transmission would require blood (from open wounds or gums) or significant mixing with other bodily fluids. The risk via kissing is considered negligible. Cleveland Clinic+1
Q: Can you get HSV-2 (genital herpes) via kissing?
A: Yes, though it is less common. HSV-2 is more often transmitted through genital contact, but transmission to the mouth is possible (especially with oral-genital contact) and then from mouth to mouth via kissing. Cleveland Clinic
Q: If someone has HPV, can kissing spread it?
A: Some types of HPV can infect the oral cavity. Transmission via heavy saliva or deep kissing is plausible especially if there are mucosal microabrasions. But for many people, oral HPV infections are cleared by the immune system without symptoms. MouthHealthy+1
Q: Should I get tested if I’ve kissed someone and feel anxious?
A: If you have symptoms (sores, etc.), or if you know your partner has an STI, yes. Even without symptoms, if you have multiple partners, or just want peace of mind, many clinics offer screening. Talk to a healthcare provider about what makes sense for your situation.
Q: Can you prevent all risk from kissing?
A: No. Some risk always remains when exchanging saliva or contacting mucous membranes. However, following preventive steps greatly reduces that risk.
Get STD Checked Today
Resources
Here are authoritative sources if you’d like to learn more or check current statistics and guidance.
- American Sexual Health Association – “Can I Get an STI from Kissing?” Asha Sexual Health
- Centers for Disease Control and Prevention (CDC) – About STI risk and oral sex CDC
- Healthline – “STD from Kissing: Diseases, Symptoms, and More” Healthline
- Cleveland Clinic – “Can You Get an STD from Kissing?” Cleveland Clinic
- Medical News Today – “STDs that can spread through kissing” Medical News Today
- ADA / MouthHealthy – “STDs of the Mouth; Types, Symptoms, and Treatment” MouthHealthy