Herpes Simplex Virus (HSV)

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 common and 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 it may “wake up” (reactivate) and cause outbreaks. How HSV affects you depends on many things, including the virus type and your overall health.

There’s no cure for HSV. But treatments can make outbreaks more manageable and lower the odds of spreading 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)

People used to link HSV-1 with oral herpes and HSV-2 with genital herpes. But that old distinction is misleading. We know that both virus types cause both types of infections.

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. You might get herpetic gingivostomatitis (sores inside your mouth) when you’re first infected. Rarely, sores affect your nose (nasal herpes).
• Genitals: A genital herpes infection causes sores in your genital area. This includes 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 around your brain and spinal cord (herpes meningitis). If HSV infects both your brain and the protective layers, it’s called herpes meningoencephalitis.
• Other organs: HSV can affect organs in your chest and belly, including your esophagus (herpes esophagitis), lungs (HSV pneumonia) and liver (HSV hepatitis). You’re more likely to get these types of infections if you’re immunocompromised.

It’s rare but possible for newborns to get herpes simplex. This is called neonatal herpes, and it can affect many different parts of a newborn’s body. It’s dangerous and needs treatment soon after birth.

What are the symptoms of herpes?

The symptoms of a herpes simplex infection are the same for females and males, but can vary by infection type:

• 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 on 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 is herpes transmitted?

You catch HSV through direct contact with someone who has an HSV infection. This means part of your body touches 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:

• If your partner has genital herpes, the virus can shed from their genital area.
• If your partner has oral herpes, the virus can shed from their mouth and saliva.

How the virus affects you depends on which part of your body touches an infected area.

What’s the herpes simplex incubation period?

It ranges from one to 26 days, but the incubation period is typically six to eight. 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 for months or years.

What triggers a herpes outbreak?

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

• Fever
• Stress
• Suppressed immune system from medications or a health condition
• Changes in hormones, like during your period

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.

How doctors diagnose HSV infections

A healthcare provider will do a physical exam and run tests. During the exam, they’ll look for signs of infection, like sores. They may take a sample 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 that you were infected with the virus in the past. Blood test results can help your provider plan treatment. But in general, they’re not routinely useful or used.

Stages of a herpes simplex infection

An HSV infection has three stages:

• Primary infection
• Latency
• Reactivation

HSV primary infection

This happens after HSV enters your body. The virus travels to nearby nerve cells, like those near your mouth or in your pelvis. It starts making copies of itself.

HSV then travels through your nerves to nearby skin or mucosa. By now, your immune system is on alert. It sends out cells that cause inflammation. This can make blisters form on your skin. You may also notice swollen lymph nodes in that area (like below your jaw or in your groin). It’s also possible to have no symptoms at this stage and not know you’re infected.

HSV latency

Within a few weeks, your immune system clears the primary infection. But HSV stays in the nerve cells it first infected. This is called latency. The virus is there in your nerve cells, but is mostly inactive or “asleep.” If enough infected cells wake up, your immune system will take notice. This leads to HSV reactivation.

HSV reactivation

This is when infected cells wake up and trigger an immune response. A few things are possible now:

• You don’t have symptoms or shed the virus. Your immune system stops the virus within hours, before it can travel to your skin or mucosa. This happens often when you have HSV. You can’t spread the virus to others during this time.
• You don’t have symptoms, but DO shed the virus. Some infected cells reach the outer layer of your skin. It’s not enough to cause symptoms, but the virus may “shed.” This means you can infect someone else through direct contact. HSV commonly spreads this way.
• You have symptoms and shed the virus. The infected cells replicate enough at your skin’s surface to cause blisters. The virus can spread to others through direct contact.

What are the treatment options for herpes?

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

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

Your provider will tell you which medicines are best for you based on the type of infection, its severity and your immune health. They’ll also let you know the proper dose and how long you need to take it.

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 outbreak. You take antiviral medicine when you first notice signs of an outbreak, like skin tingling or itching. The sooner you take it, the better it works. It can help with primary HSV infections and later outbreaks.

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 stop you from having future outbreaks or make those less severe. To do that, you need chronic suppressive therapy.

Chronic suppressive therapy

This means you take antivirals long term. Your provider might recommend this if you have genital herpes and any of the following are true:

• You have frequent or severe outbreaks
• You’re immunocompromised
• You have multiple sexual partners
• Your partners don’t have genital herpes

They may also recommend it if you have severe oral herpes outbreaks and/or at least six outbreaks per year.

For genital herpes, chronic 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, which may help protect sexual partners

When should I see my healthcare provider?

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

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?

What is the prognosis for people with herpes?

Herpes simplex is a lifelong infection. The virus may reactivate and cause outbreaks every now and then. How often it does this can vary widely from person to person. But thanks to antivirals, most people can still live normal lives in ways that are meaningful to them. Being open with your partners before having sex can foster trust and help you both feel more comfortable.

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.

Can you die from herpes simplex?

In most cases, the answer is no. But there are a couple of exceptions:

• HSV encephalitis, which affects your brain, can be fatal without treatment.
• Herpes simplex infections in newborns are life-threatening and sometimes fatal.

How do you prevent herpes simplex virus?

HSV is a common virus that spreads easily between people. So, it’s hard to prevent. 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 sex with someone who has genital sores.
• Asking partners to get tested for STIs, including herpes: You can catch HSV from someone without visible sores. Knowing a partner has HSV helps you to take precautions.
• Using protection for all sexual activity: Condoms or dental dams will not protect you 100%. But they help by covering some (but not all) areas where HSV may be shed.

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

Can you date someone with herpes and never get it?

Yes, it’s possible if all these are true: 

• Your provider is on chronic suppressive therapy
• You always use protection when you have sex
• You avoid sexual contact when your partner is having an outbreak

These precautions are important, but they’re still not a 100% guarantee. Talk to your healthcare provider about the risks and what to do in your situation.