Can you spread herpes when you don't have a cold sore?

Four out of five people have the herpes simplex virus.
Skin Problems Image Gallery Four out of five people have the herpes simplex virus. See more pictures of skin problems.
Ebby May/Taxi/Getty Images

It's not a subject mentioned real often on The Hills or American Idol, but it's a lot more relevant to our daily lives than those important shows: Herpes reportedly affects up to 80 percent of the U.S. population [source: HerpesOnline].

Yes, four out of five people have the herpes simplex virus (HSV), which causes those cold-sore blisters you sometimes see around people's lips. That's oral herpes, almost always caused HSV-1 and contracted in childhood. HSV-1 spreads like wildfire among kids -- it's passed by the briefest skin-to-skin contact, as simple as one HSV-carrying child touching a sore and then another kid in class.


Oral herpes is more common than the other, sexually transmitted type: HSV-2, the dreaded genital herpes. According to the CDC, just over 16 percent of Americans have genital herpes, primarily characterized by blisters, which then break and become sores, around any or all genital areas, including vagina, penis, anus, and buttocks [source: CDC].

Perhaps more troubling than the high infection rate for genital herpes is the fact that 85 percent of infected individuals don't know they have it [source: HerpesOnline]. With a virus that's pretty easily spread via both sexual intercourse and oral sex, that's problematic, to say the least.

It seems like it would be tough to miss the genital sores that characterize an HSV-2 flare-up and so avoid spreading the virus. Unfortunately, it's not that simple.

In this article, we'll find out precisely how herpes spreads and why extraordinary caution is required if you or your partner has or might have the disease. We'll also check out some practices that can reduce the likelihood of passing it on or contracting it.

Chances are, if you have herpes, you contracted it when your partner was having a flare-up. But recognizing a flare-up isn't as easy as it seems.



How Herpes Spreads

This color-enhanced scan shows the herpes simplex virus.
This color-enhanced scan shows the herpes simplex virus.
Ed White/Taxi/Getty Images

A recurrence is not as straightforward as "blistering genitals equals herpes episode." Blistering does mean a herpes episode, but that's not the only time it can spread.

Genital herpes is a virus and a sexually transmitted disease (see How Viruses Work to find out how viruses pass from person to person). It almost always spreads via sexual contact, through both skin-to-skin contact and through body fluids, like blood and semen. As with some other STDs, it spreads more easily from man to woman than from woman to man, because women typically experience more tearing of tissue during intercourse. During oral sex, any tear inside the mouth can lead to contraction. HSV-1 can also spread via oral sex or kissing, and both virus types can spread from one part of the body to another -- if you have a cut on your finger and you touch an open genital sore, you can end up with a herpes sore on your finger.


Herpes, when it's first contracted, occurs in three stages. The primary stage is the most obvious: That's when people usually notice something is wrong, what with all the blisters and open sores and sometimes fever, flulike symptoms, and painful or difficult urination, among other unpleasantness. The disease can spread during this stage.

In the second, "latent" phase, there are no symptoms. This is when the virus is travelling through the body, heading for your spinal nerves. The virus doesn't spread during the latent phase.

The final phase of initial infection is, for conscientious people who would never knowingly spread the disease, the most problematic. In the "shedding" stage, there are no symptoms, but the virus can spread.

To further complicate matters, some people who contract herpes never experience any noticeable symptoms at all. They may be totally unaware they're carrying the virus, but they can still spread it to their partners.

And to further, further complicate matters, even in people who do experience noticeable symptoms in their disease, herpes can spread during a flare-up when there are not yet any visible sores. The virus can still be present in the skin. This happens during a "flare-up," or recurrence, which can happen sporadically for years after the initial infection. Recurrences manifest as milder versions of the primary-infection stage, typically only with sores, fewer than during initial infection.

Given the likelihood of spreading herpes when there are no cold sores or no noticeable cold sores, keeping the virus to yourself while remaining sexually active may seem like a lost cause. But there are some precautions you can take to reduce the likelihood of passing herpes to your partner.


Ways to Limit Exposure

There are sexually active couples out there who have managed for years to prevent the spread of the disease from one partner to the other. It takes care and attention to detail, but it is definitely possible.

First, try to avoid having sex when there are any blisters or sores present. Having sex during an outbreak is the easiest way to give someone herpes.


Next, use a condom when you have sex, sores or no sores, and be sure the condom covers all the skin of the penis. Any exposed area opens the possibility of infection.

Beyond safe sex practices, for those with recognizable symptoms, not spreading the virus hinges on knowing when a flare-up is occurring even before any cold sores show up. Most often, that means looking out for a "tingling" sensation in and around the infected area. Sometimes, the skin has a mild burning feeling, and muscles nearby may feel like they're "asleep."

For those without recognizable, symptoms, it's a question of being tested. If you're sexually active, and especially if you find out any past partner is infected, get tested for herpes, either by your doctor or at a clinic. For asymptomatic carriers, being aware of your condition and using a condom absolutely every time you have sex can dramatically reduce the chances of infecting someone else.

If you do find out you're infected, unfortunately you're stuck with it. There's no cure for herpes, although there are medications that can ease symptoms and products and home remedies that can reduce discomfort during a recurrence (see the links on the next page).

The good news is, recurrences may let up after a few years, and you'll no longer have to deal with the sores. But you should always be careful not to spread it, even if your recurrences stop or slow down. There are few things worse than giving your partner an STD.

For more information on herpes and related topics, look over the links on the next page.


Lots More Information

Related HowStuffWorks Articles

  • Frequently Asked Questions About Herpes. HerpesOnline.
  • Genital Herpes. CDC Fact Sheet.
  • Herpes. FamilyDoctor.
  • Transmission.