Written by Sendra Yang, PharmD, MBA on March 22, 2026. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.
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Herpes is a very common viral infection that can spread easily.[1] There are two types: oral herpes and genital herpes. Genital herpes is a sexually transmitted infection (STI) that affects millions of people.[1]
According to the CDC, an estimated 572,000 new genital herpes infections occurred in 2018 among people ages 14 to 49. Because herpes can be transmitted without symptoms, testing plays an important role in diagnosis, treatment, and prevention.
Below, we break down how herpes testing works, how accurate it is, and what can impact your results.
How Accurate are Herpes Blood Tests?
When discussing herpes test accuracy, two important concepts are sensitivity and specificity. These terms describe how well a test correctly identifies people with and without the infection.[5]
- Sensitivity – Measures how well a test detects herpes in people who have it. For example, a test with 90% sensitivity correctly identifies 90 out of 100 infected individuals, while 10 may receive false negative results.
- Specificity – Measures how well a test identifies people who do not have herpes. For example, a test with 95% specificity correctly identifies 95 out of 100 uninfected individuals, while 5 may receive false positive results.
A highly sensitive test helps detect as many true cases as possible, while a highly specific test helps avoid misdiagnosis.
Herpes Testing
Herpes testing is important if you have symptoms or believe you may have been exposed.[1,2] There are two main types of tests:
Tests that detect the virus
- HSV Nucleic Acid Amplification Test (NAAT) – Detects herpes virus from sores or lesions. Most accurate when sores are fresh. Sensitivity ranges from 90.9% to 100%.[2]
- PCR Test – Detects genetic material of the herpes virus in sores, blood, or spinal fluid.[2,3]
- Viral Culture – Grows the virus in a lab, but is less sensitive—especially once lesions begin healing.[2,3]
Tests that detect antibodies
- Type-specific antibody tests – Detect antibodies to HSV-1 and HSV-2 and help distinguish between types.[2-4]
It’s best to consult a healthcare provider to determine which test is appropriate based on your symptoms and timing of exposure.
Interpreting Results
PCR or Viral Tests
- Positive result – Confirms active herpes infection.[2,5]
- Negative result – Does not always rule out herpes, especially if testing occurred after lesions began healing.[5]
False negatives may occur if the sample wasn’t collected properly or if the virus wasn’t actively shedding. Repeat testing may be recommended.[2]
Antibody Tests
- Positive result – Indicates past or current infection.[2,3,5]
- Negative result – May mean no exposure, or that testing occurred too soon for antibodies to develop
These tests cannot determine when the infection occurred or whether it is currently active.
Factors Affecting Test Results
Several factors can influence herpes test accuracy:[1-6]
- Timing of the test – Testing too early or too late can affect detection accuracy
- Type of test used – PCR is more sensitive than viral culture
- Sample collection – Improper collection or handling can lead to inaccurate results
- Other infections – Co-existing STIs may impact immune response and test outcomes
What to Do After Herpes Testing
If your test is positive, speak with a healthcare provider about treatment and how to reduce transmission risk.[1,2]
If your test is negative but symptoms persist, follow-up testing may be recommended—especially if testing occurred shortly after exposure.
Because herpes is an STI, it’s also a good idea to screen for other infections such as gonorrhea, chlamydia, syphilis, and HIV.
If you need guidance or treatment, you can also explore online care options and connect with a licensed provider.
Take Control of Your Health Today with Everlywell
Everlywell offers at-home STI testing options so you can check for common infections from the privacy of home—conveniently and discreetly.
All tests are physician-reviewed and designed to give you clear, actionable results so you can take the next steps with confidence.
References
- About genital herpes. Centers for Disease Control and Prevention. Accessed February 14, 2025. Medical Citation URL.
- Herpes - STI treatment guidelines. Centers for Disease Control and Prevention. September 21, 2022. Accessed February 14, 2025. Medical Citation URL.
- Asher GN, Feltner C, Harrison WN, et al. Serologic Screening for Genital Herpes: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force. JAMA. 2023;329(6):510-512. Medical Citation URL.
- Arshad Z, Alturkistani A, Brindley D, et al. Tools for the diagnosis of herpes simplex virus 1/2: systematic review of studies published between 2012 and 2018. Medical Citation URL.
- Maxim LD, Niebo R, Utell MJ. Screening tests: a review with examples. Inhal Toxicol. 2014;26(13):811–28. Medical Citation URL.
- Mathew Jr J, Sapra A. Herpes Simplex Type 2. In: StatPearls [Internet]. Updated March 13, 2024. 2025 Jan. Medical Citation URL.
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