​​How to Test for Herpes: Diagnosis and Testing

By Craig Sorkin, DNP, APN
Medically reviewed checkmarkMedically reviewed
June 29, 2022

Herpes simplex (HSV) is a virus that may or may not be sexually transmitted.

There are 2 types which can cause painful blisters and ulcers. 

Most often, HSV-1 causes oral herpes (gingivostomatitis, herpes labialis), and most often, HSV-2 causes genital lesions.

These can be interchangeable though, and sometimes genital lesions may be caused by HSV-1 or oral lesions can be caused by HSV-2.

Herpes simplex affects an estimated 3.7 billion people across the world, including nearly half of all adults under age 50 in the United States.

Understanding the signs and symptoms of herpes can help you get proper medical care and manage outbreaks.

This article covers the differences between HSV-1 and HSV-2, as well as testing, treatment, precautions, prevention, and how to know when you need to see a doctor.

How to Test for Herpes: Self-Checks

Understanding the signs and symptoms is the most obvious way to determine if you may be having a herpes outbreak.

If you have painful sores around or in the mouth, or around or in the genital or anal region, you may have herpes.

However, other sexually transmitted infections may also cause sores in the genital area.

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HSV-1 and HSV-2

Both HSV-1 and HSV-2 can cause herpes blisters.

Blisters near the mouth are frequently caused by HSV-1 and they are commonly called “cold sores.”

Blisters near the genitals are frequently caused by HSV-2 and they are sometimes called “genital herpes.”

But you won’t be able to tell which strain of the virus you have just by observing the location of the lesions because  HSV-1 can sometimes cause genital sores, and HSV-2 can sometimes cause oral sores.

The signs and symptoms of both types of herpes simplex are similar.

They may appear anywhere from 2 days to 2-3 weeks after an initial herpes virus exposure.

It is also possible to contract the virus and go years or even decades without an outbreak.

Signs and Symptoms of HSV-1

HSV-1 commonly causes painful cold sores around or in the mouth.

Less commonly, they may appear elsewhere on the face, such as the chin, cheeks, or eyes.

HSV-1 can also be transmitted via sexual contact, and may be the cause of genital sores.

Additionally, other signs of an HSV-1 infection include:

It is also possible to have HSV-1 with no symptoms, and still be contagious.

Signs and Symptoms of HSV-2

HSV-2 typically causes painful blisters around or in the genitals, anal region, or inner thighs.

It is also possible to be infected with this virus via oral sex, which could result in blisters that appear in or around the mouth.

Other signs of HSV-2 include:

  • Tingling, itching, or other sensations 1-3 days before sores appear
  • Fever
  • Fatigue
  • Swollen lymph nodes
  • Headaches
  • Body aches

You can also have HSV-2 and be able to pass the infection even without active blisters.

Types of Tests for Herpes

If you want to know for sure whether you are having a herpes outbreak, or you have no symptoms but you worry that you have been exposed to either oral or genital herpes, there are several testing options.

Herpes testing is not always included in routine STD screenings.

If you are concerned that you have herpes or that you may have had it in the past, ask your healthcare provider if testing is recommended for you.

Blood Tests for Asymptomatic Herpes

If you do not have an active outbreak of herpes blisters, your medical provider can still test to determine if you have previously been infected with either herpes simplex virus.

But, the incubation period for herpes is up to 12 days, so your doctor may recommend waiting to perform a blood test until it has been at least that long since you were exposed to the virus.

If you are tested too soon after exposure, you may get a false negative result because the immune system has not yet had time to produce antibodies

Blood tests can be done that look for antibodies to either HSV-1 or HSV-2.

The results can indicate whether you have been exposed to one or both viruses.

It is not possible to know from a blood test whether you are currently contagious with herpes, only that you have previously been infected.

It is also possible to get at-home testing kits.

These use a lancet to prick your finger and take a small blood sample, which can identify whether you have been exposed to HSV-1 or HSV-2.

If you want an at-home kit, make sure you ask your medical provider for a recommendation, as some test kits do not check for both HSV-1 and HSV-2.

Swab Testing

A medical provider can perform a physical examination of herpes blisters. 

Your medical provider may also perform a swab test during which a small sample of fluid is collected from an active herpes blister and tested to verify that it is caused by either HSV-1 or HSV-2.

Treatments for Herpes

There is no cure for herpes. But there are some treatment options that may be able to shorten outbreaks, reduce chances of future outbreaks, or alleviate symptoms from outbreaks.

  • Oral antiviral medications: Your medical provider may prescribe an antiviral medication to treat a herpes outbreak. Common medications that can treat herpes outbreaks include acyclovir (Sitavig, Zovirax), famciclovir (Famvir), and valacyclovir (Valtrex). You will need a prescription for any of these. If you have frequent outbreaks, your healthcare provider may consider treating you with a daily antiviral medication to decrease the frequency or duration of the outbreaks.
  • Topical antiviral creams: For oral cold sore outbreaks from either type of herpes, topical antiviral creams may be able to help shorten the duration by approximately one day. Some antiviral creams are available OTC, like docosanol 10% (Abreva), benzyl alcohol (Zilactin-L), and dimethicone with sunscreen (Herpecin-L). Others require a prescription from a healthcare provider. These include penciclovir cream (Denavir) or acyclovir cream (Zovirax).

Topical or OTC options work best when they are used at the first sign of an outbreak, when the tingling sensations may signal that blisters are starting to form.

Precautions and Prevention

Herpes simplex is one of the most common viruses worldwide.

Because it can spread even when people have no symptoms, it is not always possible to prevent transmission.

It is possible to reduce the risk of contracting HSV-2, which is spread via sexual contact.

You can also reduce the risk of getting HSV-1 from sexual contact by using safe sexual practices.

  • Avoid sexual activity, including kissing, with someone who has a known oral or genital herpes outbreak.
  • Use condoms or dental dams when engaging in sexual contact.
  • Do not share utensils, razors, towels, or other items that come into direct contact with herpes sores.

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When to See a Medical Provider

If you develop new sores around your mouth, in your genital area, or any other concerning area, see your medical provider.

Your healthcare provider can do a physical exam and order testing, if needed, to make sure you have an accurate diagnosis.

This can provide peace of mind and help to determine possible treatment or management options.

If you have questions about safe sexual practices, avoiding genital herpes transmission, or anything else about herpes, your healthcare provider can provide answers.

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Frequently Asked Questions

Is herpes detected in blood tests?
Yes, herpes simplex viruses can be detected in a blood test as long as it has been at least 12 days since you were exposed to the virus. If you get a blood test for HSV-1 or HSV-2 before 12 days, you may get a false negative result.
What is the most accurate test for herpes?
The most accurate way to diagnose herpes via testing depends on whether you have an active outbreak or not. If you have herpes blisters, a swab test viral culture can be done to determine if either HSV-1 or HSV-2 is causing cold sores or genital sores. If there is no active outbreak with symptoms, blood tests are the only way to determine if you have previously been exposed to either type of herpes simplex virus, although blood tests may not be able to tell you if you are actively contagious. Once your body has been exposed to HSV, your body makes antibodies. These can persist for years, so a blood test may not be able to tell you if you got infected recently or many years before.

K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.

Craig Sorkin, DNP, APN

Craig Sorkin, DNP, APN is a board certified Family Nurse Practitioner with over 15 years experience. He received his Undergraduate and Graduate degrees from William Paterson University and his doctoral degree from Drexel University. He has spent his career working in the Emergency Room and Primary Care. The last 6 years of his career have been dedicated to the field of digital medicine. He has created departments geared towards this specialized practice as well as written blogs and a book about the topic.