The herpes simplex virus is incredibly common in the United States and worldwide.

As many as 1 in 2 American adults have oral herpes, which is often caused by herpes simplex virus type 1 (HSV-1).

An estimated 1 in 8 Americans ages 14 to 49 have genital herpes from herpes simplex virus type 2 (HSV-2), which causes most cases of genital herpes.

However, either type of HSV can occur in the genital or oral region. Infection with both HSV types at the same time is also possible.

Although some people carry the virus and never experience any symptoms, others may have frequent outbreaks.

This article will examine why so many people carry the virus, how to prevent transmission, and more.

Most HSV infections are asymptomatic, so many people who carry the virus don’t know that they have it.

What’s more, the virus is easily transmitted. In many cases, all it takes is a kiss, oral sex, or genital-to-genital contact.

HSV-1

According to the American Academy of Pediatrics, most people are first exposed to HSV-1 between the ages of 1 and 5.

In these cases, oral herpes is likely the result of close contact with a parent or sibling.

For example, a parent who has HSV-1 can transmit the virus to their child if they kiss them on the mouth or share straws, eating utensils, or any other objects that have saliva with the virus on them.

A person who has HSV-1 can transmit the virus regardless of whether they’ve ever had cold sores or have an active cold sore outbreak.

HSV-2

HSV-2 infections that cause genital herpes are usually spread through sexual contact.

This includes contact with the genitals, semen, vaginal fluid, or skin sores of a person that has HSV-2.

As with HSV-1, HSV-2 can be transmitted regardless of whether it’s causing sores or other noticeable symptoms.

There are many more women than men who are infected with genital herpes as a result of HSV-2.

This is because genital herpes infection is easier to transmit from a penis to a vagina than it is from a vagina to a penis.

It’s an oversimplification to say that HSV-1 causes oral herpes and HSV-2 causes genital herpes, though these are the easiest definitions of each.

HSV-1 is a subtype of the herpes virus that typically causes oral herpes. This is also known as cold sores.

HSV-1 can also cause genital blisters that appear very similar to the genital blisters associated with HSV-2 virus.

Any herpes sore or blister — regardless of its subtype — can burn, itch, or tingle.

The HSV-2 subtype of the herpes virus causes genital sores, as well as swollen lymph nodes, body aches, and fever.

Although HSV-2 can also cause sores on the face, it’s much less common than genital sores.

It’s difficult to look at a herpes sore and determine whether it was caused by HSV-1 or HSV-2.

To make a diagnosis, a doctor or other healthcare provider would have to take a sample of fluid from a blister lesion or take a small sample of the skin lesion and send it to a lab for testing. There is also a blood test available.

Both HSV-1 and HSV-2 can cause cold sores on the mouth and face.

Although it’s more common for HSV-1 to cause cold sores, it isn’t impossible for HSV-2 to cause them, too.

Cold sores aren’t the same thing as canker sores or mouth ulcers. They each have different causes and two entirely different presentations.

Cold sores:

  • are caused by the herpes simplex virus
  • usually develop near the outside of the mouth, such as below your nostrils or on your lips
  • cause redness and fluid-filled blisters
  • usually appear in groups
  • usually burn or tingle
  • eventually break and ooze, forming a crust-like scab
  • may take up to two to four weeks to completely heal

Canker sores:

  • may be caused by food or chemical sensitivities, dietary deficiencies, minor injury, or stress
  • may develop anywhere inside your mouth, such as at the base of your gum line, inside your lip, or under your tongue
  • are shaped like a circle or oval
  • are typically yellow or white with a red border
  • may appear solo or in groups
  • usually take one to two weeks to completely heal

HSV-1 is transmitted through skin-to-skin contact, oral secretions (like saliva), and genital secretions (like semen).

Some of the ways it can be transmitted include:

  • kissing someone on the mouth
  • sharing eating utensils or cups
  • sharing lip balm
  • performing oral sex

The herpes virus usually affects the area where it first made contact with the body.

So if a person who has HSV-1 performs oral sex on their partner, their partner could contract the virus and develop genital sores.

HSV-2, on the other hand, is usually only transmitted through sexual contact. This includes genital-to-genital contact and contact with genital secretions such as semen.

Some of the ways it can be transmitted include:

When a person is exposed to the herpes virus, the virus travels through the body to nerve cells near the spinal cord known as a dorsal root ganglion.

For some people, the virus stays there latent and never causes any symptoms or problems.

For others, the virus will express itself and activate periodically, causing sores. This doesn’t always happen immediately after exposure.

Doctors don’t know exactly why some people get mouth or genital sores and others don’t, or why the virus decides to activate.

They do know that sores are more likely to develop in the following circumstances:

  • in times of severe stress
  • after exposure to cold weather or sunlight
  • after tooth extractions
  • alongside hormone fluctuations, such as pregnancy or menstruation
  • if you have a fever
  • if other infections are present

Sometimes, a person can identify the triggers that cause them to have a herpes outbreak. Other times, the triggers are seemingly random.

Major health organizations like the Centers for Disease Control and Prevention (CDC) don’t recommend screening someone for herpes unless symptoms are present.

According to the CDC, there isn’t any evidence that diagnosing the condition when symptoms aren’t present leads to a change in sexual behavior.

Although an asymptomatic diagnosis doesn’t have physical impact, it can still have a negative effect on mental health.

In many cases, the associated stigma may be more troubling than the actual diagnosis.

It’s also possible that a person who is asymptomatic could receive a false positive, resulting in needless emotional turmoil.

In most cases, you won’t know unless you develop blisters or sores on the mouth or genitals. These sores usually have a burning, tingling sensation.

If you think you’ve been exposed to HSV-2 or would like to know if you carry the virus, talk to a doctor or other healthcare provider about testing.

Yes, you can still have sex if you have HSV-1 or HSV-2.

However, you should avoid intimate contact if you’re experiencing an active outbreak. This will reduce the risk of transmission to your partner.

For example, if you have a cold sore you should avoid kissing your partner or performing oral sex.

If you have an active genital outbreak, you should avoid any below-the-belt activity until it clears.

Although the virus is less likely to spread when no symptoms are present, wearing a condom or using a dental dam can help reduce the overall risk of transmission.

You may also consider talking to your provider about prescription antiviral medication, such as:

  • acyclovir (Zovirax)
  • famciclovir (Famvir)
  • valacyclovir (Valtrex)

These medications can help suppress the virus and reduce the risk of transmission.

In rare cases, herpes can be transmitted during pregnancy or childbirth.

If you’re pregnant, or planning to become pregnant, talk to an obstetrician or other healthcare provider about the steps you can take to reduce the risk of transmission.

There is currently no cure for HSV-1 or HSV-2. The antiviral therapy for HSV suppresses the viral activity, but it does not kill the virus.

The CDC notes that any potential vaccines are being tested in clinical trials. Otherwise, vaccination against HSV is not commercially available.

If you become infected with HSV, the goal is to keep immune system functioning at a high level to help prevent active outbreaks from occurring.

Antiviral therapy may also help to prevent or shorten outbreaks from occurring.

There are actually several other subtypes of herpes viruses, which are from the same family as HSV-1 and HSV-2. This family is known as herpesviridae.

Alternatively, HSV-1 and HSV-2 are also known as human herpesvirus 1 (HHV-1) and human herpesvirus 2 (HHV-2), respectively.

The other human herpesviruses include:

  • human herpesvirus 3 (HHV-3): Also known as the varicella zoster virus, this virus causes chickenpox lesions.
  • human herpesvirus 4 (HHV-4): Also known as the Epstein-Barr virus, this virus causes infectious mononucleosis.
  • human herpesvirus 5 (HHV-5): Also known as the cytomegalovirus, this virus causes symptoms such as fatigue and muscle aches.
  • human herpesvirus 6 (HHV-6): This virus can cause a serious illness in infants known as “sixth disease,” also called roseola infantum. The virus causes a high fever and distinctive rash.
  • human herpesvirus 7 (HHV-7): This virus is similar to HHV-6 and can cause some cases of roseola.
  • human herpesvirus 8 (HHV-8): This virus can contribute to a serious illness known as Kaposi sarcoma, which can lead to connective tissue cancer.

Many of these subtypes (such as HHV-3) are contracted in childhood.

If you recently received a diagnosis, know that you aren’t alone. Most adults carry at least one form of herpes virus, if not more.

You may also find comfort in knowing that when symptoms are present, the first outbreak is generally the most severe.

Once the initial outbreak clears, you may not experience another flare-up for many months, if at all.

If you have questions about treatment, see a doctor. They can advise you on any next steps.