Herpes spreads through direct skin-to-skin contact with someone who carries the virus, even when they have no visible sores. There are two types: HSV-1, which typically causes oral herpes (cold sores), and HSV-2, which typically causes genital herpes. Both can be transmitted during periods when the infected person looks and feels completely fine.
Skin-to-Skin Contact Is the Primary Route
HSV lives in skin cells and mucous membranes, the moist tissue lining the mouth, genitals, and anus. The virus passes from one person to another when these surfaces come into direct contact. For HSV-1, that usually means kissing or touching the skin around someone’s mouth. For HSV-2, it means vaginal, anal, or oral sex with someone who carries the virus in their genital area.
The risk is highest when active sores are present, because open blisters contain large amounts of virus. But here’s the part that surprises most people: herpes frequently spreads when no sores are visible at all. The virus periodically reactivates and travels to the skin surface in a process called “shedding,” and the person shedding has no idea it’s happening. HSV-2 is especially active this way. In the first year of infection, people with genital HSV-2 shed virus on roughly 34% of days, and even a decade later, shedding still occurs on about 17% of days. HSV-1 in the genital area sheds less often, around 7% of days by the end of the first year, dropping further over time.
Oral Sex and Genital HSV-1
A growing number of genital herpes cases are caused by HSV-1, the “cold sore” virus, transmitted during oral sex. If your partner has oral HSV-1 and performs oral sex on you, the virus can infect your genital area. This can happen whether or not your partner has a visible cold sore, though the risk is much higher during an active outbreak.
Contact with any of the following can lead to transmission: a herpes sore, saliva from someone with oral herpes, genital fluids from someone with genital herpes, or simply the skin around the mouth or genitals of an infected person. You don’t need to see a blister for the virus to be present on the skin’s surface.
Can You Catch It From Objects or Surfaces?
Herpes is fragile outside the body, but it doesn’t die instantly. Lab research published in JAMA found that HSV survived up to 4.5 hours on plastic surfaces kept warm and humid, similar to conditions you’d find on a bench at a pool or spa. In theory, this means surfaces like toilet seats or shared items could carry the virus briefly.
In practice, though, catching herpes from an object is considered extremely unlikely. The virus needs a way into the body, typically through a mucous membrane or a small break in the skin, and casual contact with a surface rarely provides that. Sharing lip balm or a drinking glass with someone who has an active cold sore carries a small theoretical risk, but surface transmission is not a meaningful driver of herpes infections in the real world.
Spreading It to Other Parts of Your Own Body
It’s possible to transfer herpes from one area of your body to another, a process called autoinoculation. The most common example: touching a cold sore on your lip and then rubbing your eye. HSV-1 in the eye can cause a condition called ocular herpes, which may lead to vision problems if untreated. HSV-2 can also reach the face or eyes through hand contact, though this is less common.
Autoinoculation is most likely during a first outbreak, when your body hasn’t yet built antibodies against the virus. Once your immune system has mounted a response, the risk of spreading the virus to new sites on your own body drops significantly. Still, washing your hands after touching an active sore is a simple habit worth keeping.
Transmission During Pregnancy and Birth
A mother with genital herpes can pass the virus to her baby during delivery. The risk varies dramatically depending on timing. If a woman catches herpes for the first time near the end of pregnancy, the transmission risk to the newborn is 30 to 50%, because her body hasn’t had time to produce protective antibodies. If she had herpes before pregnancy or caught it early on, the risk drops to less than 1%, because her immune response helps protect the baby during delivery.
Neonatal herpes is rare but serious, which is why doctors screen for symptoms and may recommend a cesarean delivery for women with active sores at the time of labor.
What Happens After Exposure
If you’re exposed and the virus takes hold, the first outbreak typically appears within two weeks. It often includes clusters of small, painful blisters around the mouth or genitals, sometimes with flu-like symptoms such as fever and swollen lymph nodes. The first episode is usually the most severe.
Not everyone gets noticeable symptoms, though. Some people don’t develop their first outbreak until months or even years after infection, and others never have visible symptoms at all while still carrying and occasionally shedding the virus. This is a major reason herpes is so widespread: many people who transmit it genuinely don’t know they have it.
How to Reduce Transmission Risk
Condoms provide meaningful but incomplete protection. A large study published in JAMA found that consistent condom use reduced the risk of women acquiring HSV-2 by about 75% compared to infrequent use. The protection was less clear for men acquiring the virus from women, likely because herpes can shed from skin areas a condom doesn’t cover, such as the upper thighs or the base of the genitals.
Daily antiviral medication taken by the infected partner also lowers transmission risk, though the effect is modest in absolute terms. One clinical trial found that 62 partners needed to take daily medication for eight months to prevent a single new infection. Combining antivirals with condom use provides the best overall reduction in risk.
Avoiding sexual contact during active outbreaks is the single most effective step, since viral load on the skin is highest when sores are present. For oral herpes, that means not kissing or sharing utensils during a cold sore. For genital herpes, it means abstaining from sex until sores have fully healed. Between outbreaks, condoms and antivirals together bring the per-year transmission risk down considerably for couples where one partner is infected and the other is not.