HSV-1 vs. HSV-2: The Difference Between the Two Herpes Viruses, Explained Simply

Short answer: HSV-1 and HSV-2 are two close relatives of the same virus family. HSV-1 usually causes cold sores around the mouth, and HSV-2 usually causes genital herpes — but either one can show up in either place. Both stay in the body for life, both can be treated, and neither can be cured (WHO).

If you were just diagnosed, take a breath: herpes is one of the most common infections in the world. Most people who have it don’t even know.

HSV-1 and HSV-2 side by side

	HSV-1	HSV-2
Usually shows up as	Cold sores or “fever blisters” on or around the mouth	Genital herpes
Can it appear in the other place?	Yes. It can cause genital herpes through oral sex	Mainly genital
How it mainly spreads	Contact with sores, saliva or skin around the mouth, for example kissing	Sex: contact with genital or anal skin
People with it worldwide	About 3.8 billion under age 50 (64%)	About 520 million aged 15–49 (13%)
People with it in the US, ages 14–49	47.8%	11.9%
Cure	No	No
Treatment	Antiviral medicine shortens and softens outbreaks	Same medicines; a daily dose also cuts the risk of passing it on

Sources: worldwide numbers from the WHO (2020 estimates); US numbers from the CDC’s National Center for Health Statistics (2015–2016).

You are far from alone

Almost half of Americans aged 14 to 49 carry HSV-1, and about 1 in 8 carry HSV-2, according to the CDC’s national survey. Both numbers went down between 1999–2000 and 2015–2016, and both were higher in women than in men (CDC/NCHS).

The WHO adds that most people with herpes have no symptoms or only mild ones, which is why so many people don’t know they have it (WHO).

HSV-1: the cold sore virus

HSV-1 is the virus behind most cold sores, also called fever blisters. It spreads mainly through contact with the virus in sores, saliva or the skin around the mouth (WHO).

Cold sores often come back when something “wakes up” the virus. Common triggers include another illness or fever, sunlight, stress, and periods or other hormone changes (NHS, MedlinePlus).

HSV-1 can also cause genital herpes. The CDC says oral herpes caused by HSV-1 “can spread from the mouth to the genitals through oral sex” (CDC).

Want to make a cold sore heal faster? Read how to get rid of cold sores.

HSV-2: the genital herpes virus

HSV-2 spreads mainly during sex, through contact with genital or anal skin (WHO). Symptoms come as outbreaks: blisters that break, become painful sores and then heal. Some people have no symptoms or very mild ones (MedlinePlus).

Two facts are easy to miss:

• It can spread without a visible sore. You can get genital herpes from a partner who has no sore or doesn’t know they are infected (CDC).
• A mother can pass the virus to her baby during childbirth. If you are pregnant and have herpes, tell your doctor (MedlinePlus).

Can you have both?

Yes. The WHO explains that a person who already has HSV-1 can’t catch HSV-1 again, but can still catch HSV-2 (WHO).

How do I know which type I have?

Only a test can tell. According to the CDC, a doctor can (CDC):

1. Look at the sores.
2. Swab a sore and test the sample.
3. Order a blood test for herpes antibodies when there is no sore.

Ask which type was found. The type helps your doctor plan treatment and helps you talk with a partner.

How outbreaks are treated

There is no cure, but treatment works. Antiviral tablets — acyclovir, famciclovir and valacyclovir — can make outbreaks shorter and milder. Taken every day (“suppressive therapy”), they can also make outbreaks less frequent (WHO) and lower the risk of passing the virus to a partner (CDC).

More on this in our guide to herpes outbreaks.

How to lower the risk of passing it on

• Avoid contact during an outbreak. Don’t kiss anyone while you have a cold sore, and don’t have oral sex until it has completely healed (NHS). Avoid direct contact with any herpes sore (MedlinePlus).
• Use condoms every time. They lower the risk, but the CDC notes they “may not fully protect you” (CDC).
• Ask about daily antiviral medicine if your partner doesn’t have the same type.
• Don’t share utensils, straws, glasses or towels with someone who has a cold sore (MedlinePlus).

Do supplements help?

No supplement can remove either virus. Some people add a supplement to their routine between outbreaks, next to their doctor’s advice. The evidence for these products is limited: for example, studies on L-lysine are mixed (our lysine guide). If you are curious, we compared the options on price, refund rules and what each seller discloses in the best cold sore supplements.

When to see a doctor

• You think you have genital herpes for the first time.
• You are pregnant and have, or think you have, herpes.
• A sore is near your eye.
• Sores are very large or painful, or don’t start to heal after 10 days.
• Your immune system is weak.

(NHS, MedlinePlus)