In terms of sexual activity, the act of kissing seems pretty harmless. After all, how much can happen from a peck on the lips or even an open-mouth makeout session?
What many people don’t realize is that kissing can transfer sexually transmitted diseases (STDs) and sexually transmitted infections (STIs).
This doesn’t mean you need to stop kissing. But it is another reason to discuss your sexual history with any and all partners.
Especially if you know you have herpes simplex virus (HSV), you could pass your STI to your partner when kissing.
In this article, we’ll cover which STDs are spread through kissing, other diseases spread through kissing, and how to prevent STDs so you can take action to stay as healthy as possible—and still enjoy the sex life you want.
Which STDs Can Spread Through Kissing?
Only a few STIs and STDs can be spread through kissing, but it’s important to know that you might be at risk of contracting the following.
Two herpes viruses can be passed through kissing: The more common one is HSV-1, or oral herpes, which can cause cold sores.
HSV-2, or genital herpes, can also be passed when kissing but is most often passed through genital contact.
HSV-1 Oral Herpes
Herpes simplex virus type 1 (HSV-1) is one of the most common diseases passed through kissing.
Almost half of US adults have oral herpes. Many people contract the virus not through sexual contact but when they are a child. For example, something like a kiss from an infected parent or relative can spread the virus.
During an outbreak, HSV-1 causes red or white blisters on the mouth called cold sores or fever blisters.
The virus is most contagious when someone has these blisters or other symptoms. And if a cold sore is oozing puss or bleeding, it’s even more likely to spread the virus.
However, the virus can also spread when there are no noticeable symptoms.
If you’re swapping spit while you have a cold sore, you’re likely to pass along HSV-1. It can also spread through sharing utensils or anything that comes in contact with the virus.
It’s important to avoid kissing while you have a cold sore and use over-the-counter (OTC) medication until the cold sore goes away.
HSV-2 Genital Herpes
Herpes simplex virus type 2 (HSV-2) is most often spread through sexual acts like oral, vaginal, and anal sex.
HSV-2 symptoms also present as painful blisters, sores, and ulcers, but they happen in the genital area.
HSV-2 can spread through kissing in very limited circumstances and can cause oral herpes. However, it is more likely to get HSV-1 through kissing.
Syphilis is caused by the bacterium Treponema pallidum. It most often spreads during vaginal, oral, and anal sex when an uninfected person has direct contact with a syphilis sore. It can also spread through kissing if someone has sores on their lips or in their mouth.
Syphilis doesn’t always cause symptoms, so it’s important to be tested regularly. The infection needs to be treated with antibiotics. If syphilis goes untreated, it can cause fertility issues or other serious health problems in the future.
Human papillomavirus (HPV) is typically passed through direct contact with the genital area, but a small number of people can develop oral HPV. If your saliva is infected, you can pass the virus to your partner through deep kissing.
4% of women and 10% of men develop oral HPV in the US.
Most strains of HPV are harmless and present zero symptoms.
However, certain strains of oral HPV can cause cancer of the oropharynx, tongue, tonsils, or throat. It is likely that 70% of oropharyngeal cancer is caused by oral HPV.
Possible signs of oropharyngeal cancer include a persistent and painful sore throat, earaches, hoarseness, and sudden weight loss.
Talk to a healthcare provider if you have any concerns that you may have HPV, and if you are a good candidate for the HPV vaccine.
Your dentist may perform an oral cancer screening at your checkups, so it is important to get regular dental care.
STDs That Do Not Spread Through Kissing
While kissing can spread some STIs, most spread through vaginal, oral, or anal sex.
Don’t worry about kissing and the STIs below:
- HIV is viral infection is passed through semen, blood, vaginal and anal fluid, and breast milk. In rare cases, it could be passed by kissing if the HIV-negative person has an open sore in their mouth.
- Hepatitis is a virus spread through genital contact or infected blood.
- Gonorrhea is passed through sexual activity but not passed through saliva from kissing.
- Chlamydia is a bacterial infection spread through genital, oral, and anal sex.
- Trichomoniasis is passed through genital, oral, and anal sex.
- Pubic lice is passed through genital-to-genital contact.
Keep in mind that unprotected sex—or failure to use a barrier method—can pass along these STIs.
Other Diseases That Can Spread by Kissing
Even though only a few STIs can be passed through kissing, makeout sessions can spread other diseases. So make sure you and your partner don’t have any symptoms.
Common diseases transmitted through kissing include:
- Coronaviruses and other common cold viruses
- Common colds
Talking to Your Partner
Even if you may be nervous about having that conversation, being open with your partner can make all the difference in your safe sex journey.
It’s important to be direct and honest with your sexual partners, as this can lead to a more fulfilling sex life.
If you want to use a barrier method, like a condom or dental dam, be firm about your boundaries and expectations. It’s your body, and a good partner will respect your boundaries.
If you have an STI, let your partner know before engaging in any sexual activity. This will help stop the spread of STIs.
Lastly, be understanding with your partner and yourself. More than half of people in the US will have an STI at some point in their lifetime. So don’t jump to conclusions if your partner tells you that they have an STI.
Although it’s not possible to avoid contracting all STIs unless you’re celibate, a few things can help significantly lower your risk:
- Don’t kiss anyone with an active cold sore until their symptoms have fully subsided.
- Use barrier methods (such as condoms or dental dams) for vaginal, anal, and oral sex.
- Be open and honest with each of your partners about your sexual history and inquire about theirs.
- Limiting your number of partners. The more people you’re sexually involved with, the greater the risk of contracting an STI.
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K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.
K Health has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical associations. We avoid using tertiary references.
About Cytomegalovirus (CMV) (2020).
Herpes Simplex Virus. (2020).
HPV and Oropharyngeal Cancer. (2021).
Kissing May Spread Human Herpes Virus 8, the Cause of Kaposi’s Sarcoma, Among Men.(2000).
Prevalence of Herpes Simplex Virus Type 1 and Type 2 in Persons Aged 14–49: United States, 2015–2016. (2018).
Public Knowledge and Attitudes About Sexually Transmitted Infections: KFF Polling and Policy Insights. (2020).
Sexually Transmitted Infections Prevalence, Incidence, and Cost Estimates in the United States. (2021).