Herpes: what you need to know about this family of viruses

Mike Bohl, MD, MPH, ALM - Contributor Avatar

Written by Jefferson Chen, MD 

Mike Bohl, MD, MPH, ALM - Contributor Avatar

Written by Jefferson Chen, MD 

last updated: Oct 22, 2019

6 min read

You probably didn’t want to be searching about herpes today, did you? Before you wipe your browser history, let’s answer your burning, itching questions about herpes, its symptoms, and what to do if you think you have it.

Genital herpes

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What is herpes?

Most people, when they say “herpes,” are referring to genital herpes. (You can skip ahead to everything about genital herpes if you’re worried about that sexually transmitted infection.) Herpes is actually the name for a whole family of viruses that cause a wide range of diseases. Called herpesviridae, members of this virus family are responsible for causing chickenpox, shingles, genital herpes, oral herpes (cold sores), and mononucleosis (“mono”), among many other diseases. 

The name herpes comes from the Greek word herpein, which means “creeping” or “to creep.” This is in reference to the blisters that spread across the skin in many of the diseases that herpesviruses cause. And before you think the Greeks were ancient, humans and the herpesviruses go way back, back to even before we were human. Researchers at UCSD discovered that HSV-1 and HSV-2, the viruses that cause cold sores and genital herpes, infected Homo erectus, a precursor to modern humans, over 1.6 million years ago (Smith, 2014).

How many different types of herpes affect humans? How common are they?

Nine members of the herpesviridae virus family are known to infect humans. Conveniently, eight of them have been given the name human herpesvirus (HHV) and are numbered one through eight. The ninth—Herpes B virus—is incredibly rare but technically does infect humans. Let’s go over this fact sheet of the different viruses in this family.


Also known as herpes simplex virus-1 or HSV-1, this virus causes oral herpes (cold sores). HSV-1 is commonly spread person to person through kissing, sharing utensils, glasses, cups, water bottles, towels, lip balm, or razors, or through oral sex. It also causes some cases of genital herpes. It’s estimated that 3.7 billion people worldwide are infected by HHV-1. Learn more about cold sores here (WHO, 2017).


Also known as herpes simplex virus-2 or HSV-2, this virus causes genital herpes. HSV-2 infections are commonly transmitted from person to person during oral sex, anal sex, or vaginal sex. Genital herpes is one of the most common sexually transmitted infections (STIs), affecting more than 500 million people worldwide. Learn more about genital herpes here.


Also known as varicella-zoster virus or VZV, this virus causes chickenpox and shingles. Chickenpox is the form of the disease during the initial infection, and shingles occurs when it reactivates. Most people in the United States have either been vaccinated or were infected with VZV as a child. It’s estimated that 1 in 3 people will have shingles over their lifetime. There are effective vaccines for both chickenpox and shingles. Learn more about chickenpox and shingles here. 


Also known as the Epstein-Barr virus or EBV, this virus causes infectious mononucleosis (“mono” or IM) among other diseases. EBV is tremendously prevalent—approximately 90–95% of all adults have previously been infected with EBV (Dunmire, 2018). EBV has also been associated with the development of certain cancers, including B and T cell lymphoma, Hodgkin lymphoma, and nasopharyngeal carcinoma. 


Also known as cytomegalovirus or CMV, this virus can commonly cause a mononucleosis-like syndrome. In people with compromised immune systems and newborns, however, CMV can cause a whole host of serious problems. CMV infections in a fetus can cause hearing loss, cerebral palsy, intellectual disability, vision impairment, and seizures. In people with acquired immunodeficiency syndrome (AIDS), CMV can infect the retina and cause vision loss, in a disease called CMV retinitis (Goldberg, 2015). CMV is also very common—in the United States, around 6 in 10 people have been infected with CMV before (Staras, 2006).


A virus with two subtypes, HHV-6A and HHV-6B, HHV-6 infects most children before age 2. The classic manifestation of an HHV-6 infection is called roseola infantum and causes a high fever for three to five days and is followed by a rash. HHV-6 infections usually result in only a minor illness. In the United States, over 90% of children have been infected by age 2 (Zerr, 2005).


HHV-7 infections are generally asymptomatic, but in the rare cases it does cause symptoms, it behaves like HHV-6. Over 95% of adults have been infected with HHV-7 (Wyatt, 1991). 


HHV-8 infections are also usually asymptomatic in healthy people. More significantly, HHV-8 is associated with Kaposi sarcoma, a type of cancer of the blood vessels. Kaposi sarcoma is rare but can be seen in people with HIV once they have progressed to AIDS, transplant recipients, and cancer patients on chemotherapy.

B virus

B virus is an extremely rare form of herpes that comes from macaque monkeys. Only 50 cases of B virus have ever been documented, and only one case occurred from human-to-human contact (Cohen, 2019; CDC, 2019). Symptoms include fever, chills, muscle aches, fatigue, and headache. When B virus progresses, it can lead to severe brain damage and death.

What is genital herpes?

Let’s dive deeper into genital herpes, one of the most common sexually transmitted diseases. Genital herpes is caused by a viral infection, primarily by herpes simplex virus 2 (HSV-2), but can also be caused by herpes simplex virus 1 (HSV-1), the virus that also causes cold sores (oral herpes). The symptoms of genital herpes can vary significantly from person to person. Some people infected with genital herpes can have mild symptoms or no symptoms at all. Others experience severe, painful ulcers on their genitals, itching or burning with urination, fever, headache, flu-like symptoms, and swollen, painful lymph nodes. 

Here are the facts you need to know about genital herpes:

  • Genital herpes typically looks like small pimples or blisters that will turn into painful ulcers or open sores. Herpes sores are found on the genitals and throughout the groin area. Over time, they will crust over and then form a scab. This lasts about 2–3 weeks before going away. The first time you get symptoms is usually the worst. 

  • You can get recurrences of genital herpes multiple times a year. Stress, other illnesses, decreased immunity, sunlight, and fatigue can trigger recurrent herpes outbreaks. 

  • HSV-2 infections are commonly transmitted during oral sex, anal sex, or vaginal sex. The highest chance of transmitting an HSV-2 infection is during an outbreak, but even when there are no symptoms, there’s still a chance of spreading the virus to your sexual partner. You can’t get infected from a toilet seat

  • Latex condoms can reduce the risk of transmitting HSV-2, but there’s no way of eliminating the risk completely except through complete abstinence from sexual contact. 

  • There are a few tests available to test for genital herpes. A viral culture tries to grow the virus from a swab of a suspected blister. A polymerase chain reaction (PCR) test tries to amplify and isolate viral DNA from a sample. Serological tests use a blood test to see if your immune system has responded to the infection. 

  • There are three antiviral medicines commonly used to treat genital herpes—acyclovir, famciclovir, and valacyclovir (brand name Valtrex; see Important Safety Information). These medications are taken by mouth and can be used on an ongoing basis to prevent outbreaks, or they can be used to shorten an episode when taken at the first sign or symptom of an outbreak of herpes.

What is oral herpes?

Oral herpes, also called herpes labialis, is caused by a viral infection that causes small, painful blisters around the mouth and on the lips during an outbreak. These blisters—commonly called cold sores or fever blisters—are primarily caused by herpes simplex virus type 1 (HSV-1). HSV-1 is extremely common—worldwide, it’s estimated that 3.7 billion people are infected with HSV-1 (Looker, 2015). 

Here are the facts you need to know about oral herpes:

  • Symptoms of oral herpes include small, fluid-filled blisters in and around the mouth that last around 1–2 weeks before going away. The first outbreak you get is usually the worst.

  • 20–40% of those infected with HSV-1 will have recurrent cold sores (Spruance, 1977).

  • HSV-1 is transmitted from person to person via contact with sores, skin-to-skin contact, oral contact, or infected saliva. It’s common to spread HSV-1 through kissing, sharing utensils, glasses, cups, water bottles, towels, lip balm, or razors, or through oral sex. 

  • You’re most infectious during an outbreak. However, you can still infect others with HSV-1 even if you don’t have any symptoms of oral herpes.

  • Usually, healthcare providers diagnose cold sores just by their physical exam, no testing required

  • Treatment options include oral as well as topical antiviral medicines for episodic treatment of an oral herpes outbreak.

Why is there no cure for herpes?

Herpesviruses share a trait that makes them very difficult to deal with. They are very good at evading your immune system (Huang, 2015). First, they have the ability to go into a latent phase, during which they hide out without doing much replication or damage to your cells. Second, they affect the MHC system, which allows them to hide in plain sight and lie to your immune system, telling it that the cells they infected are completely normal cells. Finally, some herpesviruses can use your cellular machinery to create a protein called cmvIL-10, which suppresses your immune system (Spencer, 2002). 

Because of their stealth abilities, herpesviruses are usually lifelong infections. Your immune system is usually able to keep them in check and prevent them from causing symptoms of herpes infections most of the time. But when your immune system is compromised, or when you’re dealing with another illness, the virus can come back and wreak havoc. However, there are antiviral medications that can effectively treat herpesvirus infections.


If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.

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How we reviewed this article

Every article on Health Guide goes through rigorous fact-checking by our team of medical reviewers. Our reviewers are trained medical professionals who ensure each article contains the most up-to-date information, and that medical details have been correctly interpreted by the writer.

Current version

October 22, 2019

Written by

Jefferson Chen, MD

Fact checked by

Mike Bohl, MD, MPH, ALM

About the medical reviewer

Dr. Mike is a licensed physician and a former Director, Medical Content & Education at Ro.