Herpes spreads through direct skin-to-skin contact or contact with saliva from someone who carries the virus. There are two types: HSV-1, which typically causes oral herpes (cold sores), and HSV-2, which typically causes genital herpes. Both can spread even when the infected person has no visible sores, which is a major reason the virus is so common.
Skin Contact Is the Primary Route
Herpes requires direct contact with infected skin, mucous membranes, or saliva. The virus enters your body through tiny breaks in the skin or through the moist lining of the mouth, genitals, or anus. The greatest risk of transmission is when active sores are present, but the virus can also spread from skin that looks completely normal.
This is important to understand: many people who pass on herpes don’t know they have it. The virus periodically “sheds” from the skin surface without causing any symptoms. Research tracking people with genital HSV-1 found the virus was detectable on roughly 5% of days a full year after their first outbreak, even when no sores were visible. This silent shedding is why herpes spreads so effectively through the population.
How HSV-1 (Oral Herpes) Spreads
HSV-1 is the type most people pick up in childhood or adolescence. It spreads through kissing, sharing utensils, or any mouth-to-skin contact with someone who carries the virus. A parent kissing a child, a partner kissing during a cold sore outbreak, or sharing lip balm can all transmit it. The risk is highest when cold sores are present, so avoiding kissing and sharing personal items during an active outbreak significantly reduces the chance of passing it on.
HSV-1 can also cause genital herpes. If someone with oral HSV-1 performs oral sex on a partner, the virus can establish itself in the genital area. The WHO estimates that about 376 million genital herpes infections worldwide are caused by HSV-1 rather than HSV-2, largely through oral sex.
How HSV-2 (Genital Herpes) Spreads
HSV-2 spreads almost exclusively through sexual contact: vaginal sex, anal sex, and occasionally oral sex. The virus passes from the genital or anal skin of one partner to the mucous membranes or broken skin of the other. You can contract it from someone who has never had a noticeable outbreak.
Transmission doesn’t happen equally in both directions. Women are more vulnerable to acquiring HSV-2 from male partners than the reverse, likely because the mucous membranes of the vagina provide a larger entry point for the virus. One study tracking couples found that women acquired HSV-2 at roughly 19.5 per 100 person-years compared to 11.9 for men.
You Cannot Get Herpes From Surfaces
The herpes virus is fragile outside the body. It cannot survive on porous surfaces like towels, and it dies quickly on hard surfaces like toilet seats. You will not get herpes from a toilet seat, a shared towel, a swimming pool, or a doorknob. The virus needs warm, moist, direct human contact to spread. This is one of the most persistent myths about herpes, and it simply isn’t supported by how the virus behaves outside living tissue.
How Condoms and Antivirals Reduce Risk
Condoms lower the risk of herpes transmission, but they don’t eliminate it. Because herpes can live on skin that a condom doesn’t cover (the upper thighs, pubic area, buttocks), protection isn’t complete. That said, consistent condom use significantly reduces the risk for women acquiring HSV-2 from male partners. A study published in JAMA found that women whose partners used condoms for more than 25% of sex acts had a dramatically lower rate of infection. The protective effect for men acquiring herpes from women was less clear in the same study.
Daily antiviral medication taken by the infected partner also reduces transmission. The CDC notes that daily suppressive therapy with an antiviral lowers the rate of HSV-2 transmission in couples where one partner is infected and the other is not. Combining condom use with daily antivirals offers the strongest protection short of abstaining from contact during outbreaks.
Transmission During Pregnancy and Birth
A mother can pass herpes to her baby, most commonly during vaginal delivery if she has an active genital outbreak at the time of birth. The baby contracts the virus while passing through the birth canal. Infection during pregnancy (in the uterus) is possible but rare. A newborn can also be infected shortly after birth through contact with someone who has active cold sores, such as being kissed by a relative with an oral outbreak.
Neonatal herpes is serious, which is why doctors closely monitor pregnant women with a history of genital herpes. If an active outbreak is present at the time of labor, a cesarean delivery is typically recommended to protect the baby.
Why So Many People Have It Without Knowing
Most herpes infections produce mild symptoms or none at all. Many people carry the virus for years without ever having a recognizable outbreak. They may experience occasional mild irritation they attribute to something else, or they may shed the virus with zero symptoms. This is the core reason herpes is so widespread: the majority of transmission happens when the person passing it on has no idea they’re infectious. If you’re sexually active and want to know your status, a blood test can detect herpes antibodies even if you’ve never had symptoms.