Herpes Simplex Virus (HSV)

What is herpes simplex virus?

Herpes simplex virus (HSV) can infect many different parts of your body, most commonly your mouth area (oral herpes) and genitals (genital herpes). HSV causes fluid-filled blisters that break open and crust over wherever the infection is. This is known as a herpes outbreak. But it’s also possible to have no symptoms and not realize you’re infected.

HSV is highly contagious. It spreads from person to person through skin-to-skin contact. A herpes simplex infection occurs when the virus enters your body through your skin and mucous membranes (mucosa). The virus uses your cells to make copies of itself (replication).

Once you’re infected, the virus stays in your body for life. It’s usually asleep (dormant) but may “wake up” (reactivate) and cause outbreaks. How HSV affects you depends on many factors, including the specific virus type and your overall health.

There’s no cure for HSV. But treatments can help make outbreaks more manageable while lowering the chances that you’ll spread the virus to others.

Types of herpes simplex virus

There are two types of herpes simplex virus:

• Herpes simplex virus type 1 (HSV-1).
• Herpes simplex virus type 2 (HSV-2).

Both HSV-1 and HSV-2 can cause oral herpes or genital herpes. They also cause infections in other areas of your body.

What parts of the body does HSV affect?

Herpes simplex virus can cause infections in your:

• Mouth and face. An oral herpes infection causes cold sores on your lips and around your mouth. Some people develop herpetic gingivostomatitis (sores inside their mouths and other symptoms) when they first get infected. Rarely, sores develop on or inside your nose (nasal herpes).
• Genitals. A genital herpes infection causes sores in your genital area, including the parts you can see (like your vulva or penis) and those you can’t see (like your cervix).
• Skin on other areas of your body. HSV can infect your fingers (herpetic whitlow) or skin anywhere on your body (herpes gladiatorum). Eczema herpeticum, a widespread skin infection, is a complication of HSV infection that affects people with atopic dermatitis.
• Eyes. HSV can cause a serious eye infection called herpes keratitis (a type of ocular herpes).
• Brain and spinal cord. HSV can infect your brain (herpes simplex encephalitis) or the protective layers surrounding your brain and spinal cord (herpes meningitis). If HSV infects both your brain and its protective layers, you can develop a life-threatening condition called herpes meningoencephalitis.
• Other organs. HSV can affect one or more organs in your chest and belly, including your esophagus (herpes esophagitis), lungs (HSV pneumonia) and liver (HSV hepatitis). These types of infections are more likely to affect people who are immunocompromised.

What are the symptoms of a herpes simplex infection?

The symptoms of an HSV infection vary according to the specific type of infection:

• Oral herpes. Blisters on your lips or around your mouth. Skin may tingle, itch or burn up to 48 hours before blisters appear.
• Genital herpes. Blisters on and around your genitals. Symptoms in the 48 hours leading up to blisters appearing include fever, headache, swollen lymph nodes and itching or tingling in your genital area.
• Herpes gladiatorum. Blisters anywhere on your skin but usually your hands, face, ears or chest.
• Herpetic whitlow. Blisters on your fingers, discolored skin around your fingernail, swelling in your finger.
• Herpes keratitis (eye herpes). Eye pain or irritation, feeling like there’s something in your eye, sensitivity to light, blisters on your eyelids or around your eyes.
• HSV encephalitis. Headache, fever, focal seizures, changes in speech or behavior.
• Herpes meningitis. Headache, fever, sensitivity to light.

How do you get an HSV infection?

You catch HSV through direct contact with someone who has an HSV infection. This means part of your body needs to touch someone else’s:

• Herpes sores (oral or genital).
• Skin or mucosal surfaces (like mouth, vagina or anus), with or without visible sores.
• Saliva, semen or vaginal discharge, with or without signs of an infection.

Someone with HSV doesn’t transmit (or “shed”) the virus from every part of their body. They only shed it from the area that’s infected. Usually, that’s the part of their body where HSV first entered.

For example, someone with genital herpes can transmit the virus through the skin, mucosa and bodily fluids in their genital area only. They won’t spread HSV through their saliva — the exception, of course, is if they also have oral herpes (we’ll return to this later).

Similarly, if your partner has oral herpes but not genital herpes, then you don’t have to worry about getting HSV from contact with their genitals. You’d only be at risk of catching HSV through contact with your partner’s mouth or saliva.

If your partner has both oral and genital herpes, then it’s possible you could catch HSV from contact with their mouth area or their genital area. But exactly how the virus affects you would depend on which part of your body made that contact. This deserves a closer look.

How HSV spreads from person to person

HSV usually spreads in the following ways:

Herpes simplex incubation period

The incubation period for herpes simplex infections ranges from one to 26 days but is typically six to eight days. This is how long it takes for you to develop symptoms after first getting infected with HSV.

Some people get infected but don’t develop symptoms right away. Instead, symptoms may not appear for months or even years until the virus reactivates.

What triggers herpes simplex virus?

Triggers that may cause an oral or genital herpes outbreak include:

• Fever.
• Stress.
• Suppressed immune system (due to medications or an underlying condition).
• Changes in hormones (for example, during menstruation).

Potential triggers specific to oral herpes include:

• Sun exposure.
• Upper respiratory infection.
• Trauma to your mouth area.

Outbreaks can also occur randomly without any obvious trigger.

What are the stages of a herpes simplex infection?

An HSV infection has three stages:

• Primary infection.
• Latency.
• Reactivation.

HSV primary infection

A “primary infection” is what happens after HSV enters your body. The virus travels to nearby nerve cells, where it starts replicating. When HSV enters your mouth, it typically infects your trigeminal nerves. When it enters your genital area, it typically infects your sacral plexus (a network of nerves in your pelvis).

HSV then travels through your nerves to nearby skin or mucosa. By this point, your immune system recognizes there’s an invader, and it starts sending out immune cells. This leads to inflammation and the formation of blisters on your skin. You may also notice swollen lymph nodes in that area (for example, underneath your jaw or along your groin).

For some people, a primary infection causes no symptoms and they’re unaware they’re infected with HSV.

HSV latency

Within a few weeks, your immune system clears up the primary infection, but HSV stays in the nerve cells it first infected. Healthcare providers refer to this as latency. It means the virus is present in your nerve cells but mostly inactive (you might hear this described as the virus being “asleep”).

During latency, most of the infected cells are sleeping, but a few are awake at any given time. Usually, this doesn’t cause an outbreak. Sometimes, infected cells “wake up” and cause enough of a stir that your immune system notices. This is HSV reactivation.

HSV reactivation

Reactivation is when infected cells wake up and trigger an immune response. There are a few possibilities at this point:

• Containment in nerve tissue. There’s brief HSV activity but it begins and ends in your nerve cells. Your immune system contains the virus before it can travel to your skin or mucosa. This happens often in people with HSV — the virus wakes up, has a quick burst of activity (lasting about two to six hours) and then that’s it. You don’t shed the virus or have symptoms, and you don’t spread HSV to others.
• Asymptomatic viral shedding. Some infected cells reach the outer layer of your skin (epidermis). There’s not enough viral activity to cause symptoms, but the virus may “shed.” This means the virus can leave your skin and infect someone else through direct contact. HSV commonly spreads from person to person during this shedding period.
• Symptomatic herpes outbreak. The infected cells replicate enough at your skin’s surface to cause symptoms. This is when you notice blisters on your skin, and it’s what most people associate with a herpes outbreak. The virus can easily spread to others through direct contact.

How do healthcare providers diagnose HSV infections?

Healthcare providers diagnose HSV infections by doing a physical exam and testing. During an exam, your provider will look for signs of infection (like sores). They may take a sample from the sores to send for lab testing. If your provider suspects encephalitis and/or meningitis, they may do a spinal tap.

If you don’t have sores, your provider can use a blood test to check for antibodies against HSV-1 or HSV-2. Antibodies are a sign you’ve been infected with the virus in the past. Test results help your provider plan treatment.

What is the treatment for herpes simplex infection?

Prescription antiviral medications are the main treatment for HSV infections. These come in different forms, including:

• Pills you swallow.
• Cream or ointment you apply to your skin.
• Medication your provider gives you intravenously (through an IV).
• Drops you put into your eyes (for ocular herpes).

Your provider will tell you which type(s) of medication are best for you based on:

• The type of infection you have.
• Its severity.
• How well your immune system is working.

They’ll also tell you the proper dose and how long you’ll need the medication.

Treatment for oral and genital herpes falls into two categories: episodic therapy and chronic suppressive therapy.

Episodic therapy

This is short-term treatment that targets a single episode (outbreak). It involves taking antiviral medication when you first notice signs of an outbreak, like skin tingling or itching. The sooner you take it, the better it works. Providers use episodic therapy for primary HSV infections as well as recurrences.

Episodic therapy can:

• Make symptoms less severe.
• Help pain go away faster.
• Help sores heal faster.
• Lower the amount of virus that sheds from your skin.

Treating a single outbreak does not affect future outbreaks. Episodic therapy won’t stop you from having future outbreaks or affect their severity. To do that, you need chronic suppressive therapy.

Chronic suppressive therapy

This is when you take antiviral medications long-term. Providers recommend this approach for people who have genital herpes and:

• Experience frequent or severe outbreaks.
• Are immunocompromised.
• Have multiple sexual partners or partners who don’t have genital herpes.

Providers also recommend chronic therapy for people who have severe oral herpes outbreaks and/or at least six outbreaks per year.

Specific medications your provider may prescribe include:

• Acyclovir.
• Valacyclovir.
• Famciclovir.

Providers typically use chronic suppressive therapy for people with genital HSV-2. They don’t recommend it often for genital HSV-1 because this type causes fewer outbreaks.

Chronic suppressive therapy can:

• Lower the number of outbreaks you experience by 70% to 80%.
• Make symptoms less severe.
• Reduce viral shedding when you don’t have symptoms. This may help protect sexual partners.

Can HSV infections be prevented?

HSV is a common virus that spreads easily between people. So, it’s hard to prevent it. But you can lower your risk by:

• Avoiding close contact with people who have an HSV outbreak. For example, don’t kiss someone who has a cold sore or have sexual contact with someone who has genital sores.
• Asking partners to get tested for sexually transmitted infections (STIs), including herpes. You can catch HSV from someone who’s asymptomatic (no sores). Knowing a partner has HSV helps you to take precautions.
• Using protection (like condoms or dental dams) for all sexual activity. These will not protect you 100%. But they’ll lower the risk of HSV spreading between partners. Protection doesn’t cover all areas where HSV may shed. But they do cover some areas. Plus, they’ll help protect you against other STIs.

If you have oral herpes or genital herpes, have an open conversation with sexual partners about their risk. Both forms of HSV can spread through various forms of sexual activity. Make sure you and your partner are on the same page about precautions and testing.

Does herpes go away?

No, herpes simplex is a lifelong infection. The virus may reactivate and cause periodic outbreaks. How often it does this varies widely from person to person.

Most people with oral herpes have fewer outbreaks as they get older, particularly after age 35. Similarly, the frequency of genital herpes outbreaks typically goes down over time. Genital HSV-1 causes fewer outbreaks than genital HSV-2.

When should I see my healthcare provider?

Contact a provider if you have symptoms of an HSV infection or were exposed to HSV. Your provider will tell you if you need an exam or testing.

What questions should I ask my provider?

If you have oral or genital herpes, it may help to ask your provider:

• What treatments do you recommend?
• How can I lower the risk of spreading HSV to others?
• What are the chances HSV could spread to other parts of my body?
• How can I prevent outbreaks?

Is HPV herpes simplex?

No, HPV and herpes simplex are two different viruses. HPV stands for human papillomavirus, and it’s not part of the herpes family of viruses. But both HPV and HSV:

• Are very common.
• Are highly contagious.
• Spread through skin-to-skin contact.
• Can affect your genitals.

Does everyone have herpes simplex?

No, but HSV is a very common virus. Researchers estimate that in 2016, about 3.7 billion people around the world carried antibodies for HSV-1 (this means blood tests showed evidence of a prior HSV-1 infection). That same year, almost 500 million people carried antibodies for HSV-2.

Can you donate blood if you have herpes simplex?

Yes, but only if all the following are true:

• You’re not experiencing an outbreak.
• Any recent sores (oral or genital) are dry and almost healed.
• You meet other eligibility requirements for donating.

Talk to your healthcare provider or the place where you intend to donate blood to learn more about eligibility.

A note from Cleveland Clinic

Herpes simplex is anything but simple. It’s a sneaky virus that can spread even when a person doesn’t have symptoms. It also can affect many different parts of your body besides the ones you often hear about.

But that doesn’t mean HSV has to complicate your life. Thankfully, antiviral medications make HSV much easier to manage than in the past. If you think you have an HSV infection, contact a healthcare provider. They know how common this virus is and they’re prepared to help you live with it.