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Herpes Simplex Virus Explained

Genital herpes is a sexually transmitted disease that causes sores in the genital area. It is dormant most of the time but you can have recurring outbreaks. Another type of herpes virus causes cold sores on the mouth. Antiviral medications reduce the severity of sores and time it takes for them to go away.
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Written by
Priyanka Gimbel, MD, MPH.
K Health - Telemedicine
Last updated September 29, 2021

Herpes simplex virus questionnaire

Use our free symptom checker to find out what's causing your herpes simplex virus.

Herpes simplex virus questionnaire

Use our free symptom checker to find out what's causing your herpes simplex virus.

Herpes simplex virus symptom checker

The herpes simplex virus (HSV) is a group of viruses that can cause oral and genital sores. It is transmitted through intimate or sexual contact. The herpes virus never goes away after you have been infected by it. But it is often dormant, meaning you have no active sores.

Flare-ups can be triggered by emotional stress or physical stressors that can lower the strength of your immune system. Although there is no cure for herpes, most people with herpes only have occasional outbreaks that can be minimized with antiviral medications.

What can cause a herpes outbreak?

“Two of the most common triggers for a herpes outbreak are sunburns and excessive sun/UV exposure. If you find that these are triggers for your outbreaks, make sure to wear sunscreen on your face any time you go outside, reapply the sunscreen frequently, and avoid being outside during the sunniest parts of the day, which is typically from 10 am to 2 pm.” —Dr. Priyanka Gimbel

Types of herpes

The two main types of herpes are oral (HSV-1) and genital (HSV-2). Nearly half of Americans have HSV-1 (which causes cold sores). Much fewer people have HSV-2 (which causes genital sores). Very uncommonly, neonatal herpes can infect infants, and this can be a very serious infection that can spread to multiple organs.

These herpes viruses are part of a larger group, called herpesviridae, which also includes illnesses such as chickenpox, shingles, and mononucleosis.

Oral herpes (HSV-1)

HSV-1 causes cold sores on the lips that can come back a few times a year.

Extremely common: About 48% of Americans between the ages of 14 and 49 had HSV-1 as of 2015-2016 [source: CDC].

Main symptoms:

  • Painful “cold” sores that appear small, raised, and fluid-filled around or on the lips. You may notice itching or tingling about 24 hours before one develops.
  • The first outbreak tends to be the most painful because people typically get a cluster of mouth sores and other symptoms such as fever, headache, sore throat, and swollen lymph nodes.

How it’s transmitted: HSV-1 is transmitted when a person with active sores has intimate or sexual contact, such as kissing or oral sex with another person.

Genital herpes (HSV-2)

Genital herpes is a sexually transmitted infection that causes recurrent sores in the genital area.

Common: Genital herpes affects an estimated 12% of people ages 14 to 49 in the U.S. [source: CDC].

Main symptoms:

  • During the first outbreak, symptoms may include painful genital ulcers, burning while urinating, swollen pelvic lymph nodes, and body-wide symptoms such as muscle aches, fever, and headache.
  • Future outbreaks may only cause a cluster of painful, clear fluid-filled bumps in the genitals.

How it’s transmitted: Genital herpes is transmitted when a person with HSV-2 has sexual contact (e.g., oral, anal, or vaginal intercourse) with someone else. The risk of transmission is highest if you have an active outbreak, but there is still a small risk of spreading to others between outbreaks. Safe sexual practices, such as using condoms and avoiding contact during outbreaks, can reduce its spread.

Herpes simplex virus questionnaire

Use our free symptom checker to find out what's causing your herpes simplex virus.

Herpes simplex virus symptom checker

Neonatal herpes

Pregnant women with genital herpes can pass neonatal herpes to their infant during a vaginal delivery. It can be a serious infection.

Uncommon: it is estimated that neonatal herpes occurs in .01% to .03% of live births [Source: UptoDate].

Main symptoms: Neonatal herpes can appear in one of three different ways in neonates:

  • Local infection of skin, eye, or mouth that typically look like clusters of clear fluid-filled bumps in or around these areas
  • Infection of the nervous system, which may cause seizures, tremors, poor feeding, lethargy, and abnormal temperatures (high or low)
  • Multi-organ disease, which can cause different symptoms depending on which organs are affected. (If it's the lungs, it can cause trouble breathing; if it's the liver or intestines, the belly can swell; if bone marrow is affected, it can cause easy bruising and bleeding.)

How it’s transmitted: Pregnant women with genital herpes may pass it to their infant during a vaginal delivery, even if a woman does not have active sores.

To reduce the risk, your doctor may advise you to take antiviral medications during the last few weeks of the pregnancy. If you have an active outbreak during delivery or have warning symptoms that you may have an outbreak soon (e.g., tingling, burning, etc), then a C-section may be suggested to reduce the risk of transmission to the infant.

Neonatal herpes can also occur after birth if a person with an active HSV infection kisses an infant when they have cold sores or comes in close contact with the infant after touching any herpes sores.

Does herpes simplex affect pregnancy?

“If you are pregnant and have a history of herpes or think you might have it, make sure to tell your doctor right away. There is a small risk of herpes spreading to your baby during delivery, and this can cause serious problems in the baby. But there are ways to keep your baby safe, such as with antiviral medications to reduce the risk of spreading. “—Dr. Gimbel

How to prevent herpes from spreading

The herpes virus is most contagious from the time just before you have an outbreak of sores to the time the sores heal up completely. However, there is still a risk of spreading the herpes virus even if you do not have any symptoms of an outbreak.

According to some studies, you have about a 10% risk of getting genital herpes from an infected person if you have intimate or sexual contact with that person. If you have herpes, it is best to discuss with any sexual partners and close contacts to figure out ways to reduce transmission if they have not previously been infected. You should also talk to your doctor about a prescription for antivirals to reduce outbreaks. Below are some tips to keep in mind:

  • Use barrier contraception when having sexual intercourse of any kind (oral, vaginal, anal): Use condoms and dental dams to practice safe sex and reduce the risk of getting and spreading herpes.
  • Avoid intercourse and kissing others if there are sores present: Condoms and dental dams are not 100% effective, so avoid skin to skin contact if you have an active herpes flare. That period begins with the moment you feel any symptoms of a break-out until the sores have completely gone away.
  • Take prescription antiviral medications: Antiviral medications, such as acyclovir and valacyclovir, may be prescribed to reduce the length of a herpes outbreak and reduce the time it can spread to others. These medications are typically taken at the start of an outbreak, but your doctor may recommend daily prescription antivirals if you are prone to frequent outbreaks. There are some over-the-counter topical antiviral creams available such as Abreva, but these are not as effective.
  • Practice good hand hygiene: Make sure to wash your hands with soap and water thoroughly after touching any sores.
  • Communicate with your partner: It is important to talk with your partner if you have herpes so you can reduce the risk of spreading infections between each other.
  • Tell your doctor if you are pregnant and have a history of genital herpes: This is important so your doctor can prescribe antiviral medication during the last few weeks of pregnancy or determine if a C-section is needed.

The science behind herpes breakouts and flare-ups

Herpes outbreaks can be triggered by emotional stress or physical stressors (such as sunburn/excessive sun exposure, another illness or fever, surgery, or conditions that compromise your immune system such as cancer, HIV, certain medications, etc).

Some people rarely have flares and others may have them once a month. A herpes flare usually lasts about 5 to 8 days without any antiviral medication and is most painful in the first 24 hours of the flare.

Is herpes simplex 1 contagious?

“You can spread herpes to others even when you do not have sores, but the risk is smaller compared to when you do have sores. To reduce the risk of transmission in between outbreaks, practice safe sexual practices, use good hand hygiene, and speak to your doctor about whether taking a prescription antiviral medication is right for you.”—Dr. Gimbel

How herpes is diagnosed

Self-assessment and doctor exams

You can monitor yourself for small raised fluid-filled bumps on or around the border of the lips or in the genital area.

The doctor will do a physical examination to carefully inspect the sores and will unroof them (peel away the top of the sore) to sample the liquid inside with a swab. This swab will be sent to a lab to see if the HSV virus is present.

What does it mean to have HSV antibodies?

Your body typically develops HSV antibodies a few weeks to a few months after your first exposure to HSV. The antibodies will be in your body forever and can be detected through a blood test.

Keep in mind that antibodies tell us about our history but it does not necessarily tell us about the present. In other words, having antibodies does not mean you have an active HSV infection. In order to confirm an outbreak, a sampling of the substance inside any sores would have to test positive for the HSV virus (this is most commonly done with a PCR test or viral culture).

Conditions commonly mistaken for herpes

  • Pimples can appear on the border of the lips and in the groin area, though they tend to be raised, painful bumps with a red base and a white or black center. They often have pus that comes out if they open up.
  • Ingrown hairs can occur in areas that you shave, including near the lips or groin area. This happens as the hair starts to grow back in but gets blocked or grows in a different direction than normal. They typically look like a single red, raised, painful bump, and may have a white head and white/yellow discharge.
  • Warts can appear like a little stalk of cauliflower or a slightly raised rough patch of skin with multiple tiny black dots. They most often appear on the hands and feet but can also appear in the genital area.
  • Canker sores are round, flat sores with a white or yellowish center and are quite painful. They are found on the inside of the lips, cheeks, gums, or tongue.

Herpes simplex virus questionnaire

Use our free symptom checker to find out what's causing your herpes simplex virus.

Herpes simplex virus symptom checker

How to heal herpes sores

Both genital and oral herpes are treated with antiviral pills that are taken when you have an outbreak. These pills can help reduce the severity and duration of symptoms. Most outbreaks go away on their own within 5 to 8 days without pills.

If you have frequent outbreaks, you may be prescribed a daily antiviral medication to reduce how often you experience outbreaks. There are also over-the-counter antiviral creams (such as Abreva) that can decrease the discomfort.

Prescription antivirals

Acyclovir

Effective for: oral, genital, and neonatal herpes

Recovery speed: Can clear up oral and genital herpes 1-2 days faster than without any treatment. Infants will improve within 3–5 days of treatment but may need to continue taking the medication for up to 21 days depending on the severity of the infection.

Valacyclovir

Effective for: oral and genital herpes

Recovery speed: can clear up oral and genital herpes 1–2 days faster than without any treatment.

Famciclovir

Effective for: oral and genital herpes

Recovery speed: can clear up oral and genital herpes 1–2 days faster than without any treatment.

Other treatments

  • Take over-the-counter pain medication like ibuprofen (Advil) or acetaminophen (Tylenol).
  • Apply cold compresses to the sores, or soak in a tub if you have genital sores.
  • Avoid sexual or intimate contact with others during an outbreak until sores are completely gone to reduce the risk of spreading it.
  • Avoid spicy or acidic foods, which can irritate sores.
  • Do not pick at the sores.
  • Wash your hands after touching sores.
  • Wear loose clothing if you have genital sores to avoid irritation.
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K Health - Telemedicine
Dr. Gimbel is a board-certified Family Medicine physician and writer/reviewer for Buoy Health. She received her undergraduate degree in Neuroscience with a minor in Sociology from the University of Illinois at Chicago (2008) and graduated from the University of Illinois at Chicago College of Medicine and School of Public Health (2013). She completed a family medicine residency at the University of...
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