Short answer
The American Sexual Health Association says symptoms of genital herpes may show within days after you contract it, or they may wait weeks, months, or years. MedlinePlus says many people with genital herpes never have sores.
Checked September 28, 2026 · Sources: CDC, WHO, MedlinePlus, ACOG, ASHA, listed at the end · This site is run by an employee of the company that owns PositiveSingles. Why that matters
How long can you have herpes without knowing?
There is no single length of time. A person may show symptoms within days after contracting genital herpes, or it may take weeks, months, or years.
If a first outbreak does happen, MedlinePlus says it most often comes within 2 days to 2 weeks of being infected. The Office on Women's Health says the first signs usually show up two to 12 days after sexual contact with someone who has herpes.
Most people with oral herpes do not have any symptoms. People with HSV-1 antibodies often have an oral infection acquired during childhood, which might be asymptomatic. The HSV-1 and HSV-2 guide separates the types.
Even though you may not have a genital herpes outbreak for long periods of time, you can still pass the virus to another person at any time. See the guide to spread without an outbreak.
How many people have herpes and don't know it?
Most people with genital herpes do not know they have it. Of those testing positive for HSV-2 infection, 81.1% said they had never been told by a doctor or health-care professional that they had genital herpes.
That survey covered people aged 14 to 49 in the United States in 2005 to 2008.
Most people with genital herpes have no symptoms or have very mild symptoms.
Mild symptoms may go unnoticed or be mistaken for a pimple or an ingrown hair.
The majority of people infected with HSV-2 have not had the condition diagnosed. Many of them have mild or unrecognized infections but shed virus intermittently in the anogenital area. So most genital herpes infections are passed by someone who does not know they have it, or who has no symptoms at the time.
From NHANES in 2015 to 2016, an estimated 11.9% of people aged 14 to 49 in the United States are infected with HSV-2. The National Center for Health Statistics brief on that survey says HSV-1 and HSV-2 are common, lifelong infections that often have no symptoms.
The World Health Organization says most HSV infections are asymptomatic or unrecognized, and that many people are not aware they have the infection and can pass the virus on without knowing.
The Office on Women's Health says most women with genital herpes do not know they have it.
Can herpes stay dormant for years?
Yes. In the ganglion, the virus remains inactive (“latent”) for an indefinite period of time.
The virus lives inside nerve cells and alternates between inactive and active. After a first infection it travels to nerve cells near the spine and stays there. A trigger can make it active again, and triggers can include illness, stress, and hormonal changes. The virus could also become active with no itch, no pain, no pimples, and no blisters.
Intermittent asymptomatic shedding occurs among persons with HSV-2 genital herpes infection, even those with longstanding clinically silent infection.
The virus stays in your body for life, and some people never have another episode. HSV-2 is often passed with no symptoms, even when the skin looks normal.
Can a test tell when you got herpes?
No. It cannot tell you who gave you the infection or when you got the infection.
It can still help determine whether you have the infection.
Blood tests do not actually detect the virus. They look for antibodies, and a positive result when you have never had an outbreak means exposure at some time in the past. A positive IgG does not tell a recent infection from one that has lasted for years, because IgG appears soon after infection and stays for life.
IgM testing for HSV-1 or HSV-2 is not useful, because the tests are not type specific and might be positive during recurrent genital or oral episodes. HSV IgM testing is not recommended. An IgM result does not mean the infection is new. IgM can appear during a recurrence in up to a third of people who have been infected for some time.
After exposure, it can take up to 16 weeks or more for current tests to detect infection.
A blood test too soon after an infection could be wrong.
Type-specific HSV-2 antibody tests have a sensitivity of 80% to 98%, and false-negative results might be more frequent at early stages of infection, so the CDC's treatment guidelines recommend repeat testing 12 weeks after a recent suspected exposure.
ASHA recommends waiting 12 to 16 weeks from the last possible exposure before a type-specific blood test, so antibodies can reach detectable levels.
A low positive on the common HSV-2 blood test is often wrong, and it needs a second kind of test before anyone reads it as the answer. It still does not say when you got the infection. The most commonly used test, HerpeSelect HSV-2 enzyme immunoassay (EIA), often is falsely positive at low index values (1.1–3.0)
The herpes test guide compares a swab with a blood test. The guide for after you slept with someone who has herpes covers the same wait.
Does a new herpes diagnosis mean someone cheated?
It can be difficult to know when, and from whom, you may have contracted the virus. You can get genital herpes from a sex partner who has no visible sore, or who does not know they are infected.
If you have been sexually active, you may already have been exposed to herpes. You may have it and not know it. In fact, if you and your partner have had sex, it's possible your partner got herpes from you.
For oral herpes, the CDC says: Most people with oral herpes get it during childhood or young adulthood from non-sexual contact with saliva.
Lack of symptoms in a person who is HSV-1 seropositive does not distinguish anogenital from orolabial or cutaneous infection, and, regardless of site of infection, these persons remain at risk for acquiring HSV-2.
If you both have results, read when both partners have herpes.
What should you do after a positive result?
If you have a sore, get it swabbed before it crusts over or starts healing. Those tests work best. Ask which infections they are testing you for and which they are not, and why.
If the blood draw was soon after sex, follow the wait described above, and ask for a type-specific test. A type-common antibody test does not tell HSV-1 from HSV-2. ASHA also does not recommend using a blood test to determine how long you have had herpes.
There is no cure for genital herpes. Medicine is often used for a first outbreak or a recurrence. It can shorten symptoms and make them less severe, but it does not eradicate latent virus, and after you stop, it does not change the risk, frequency, or severity of later recurrences. Everyone with a first episode of genital herpes should receive antiviral therapy.
The first disclosure guide covers wording and timing. The dating after a diagnosis guide covers the weeks after the diagnosis.
The CDC does not recommend a herpes blood test for someone with no symptoms in most situations. A wrong result is possible, and more likely if that person's risk is low. Whether herpes is a big deal covers what the infection does in the body.
Sources
- CDC, About Genital Herpes. Most people with genital herpes have no symptoms or have very mild symptoms. Because of this, most people do not know they have a herpes infection. Mild symptoms may go unnoticed or be mistaken for other skin conditions like a pimple or ingrown hair. However, most people with oral herpes do not have any symptoms. Most people with oral herpes get it during childhood or young adulthood from non-sexual contact with saliva. A herpes blood test can help determine if you have herpes infection. It cannot tell you who gave you the infection or when you got the infection. There is no cure for genital herpes. Even if you do not have any symptoms, you can still infect your sex partners. You also can get genital herpes from a sex partner who does not have a visible sore or is unaware of their infection. Feb. 20, 2024. Read 2026-09-28.
- CDC, Screening for Genital Herpes. After exposure, it can take up to 16 weeks or more for current tests to detect infection. For example, if a person gets a blood test too soon after an infection, the result could be wrong. They can also take a sample or swab from a blister or sore that is not already crusted over or healing. In fact, the tests that use these samples work best. Ask them which infections they are and are not testing you for and why. CDC does not recommend herpes testing for people without symptoms in most situations. This is because of the limits of a herpes blood test and the possibility of a wrong test result. The chances of wrong test results are higher for people who are at low risk of infection. Feb. 20, 2024. Read 2026-09-28.
- CDC, STI Treatment Guidelines, genital herpes. The majority of persons infected with HSV-2 have not had the condition diagnosed, many of whom have mild or unrecognized infections but shed virus intermittently in the anogenital area. Consequently, most genital herpes infections are transmitted by persons unaware that they have the infection or who are asymptomatic when transmission occurs. Intermittent asymptomatic shedding occurs among persons with HSV-2 genital herpes infection, even those with longstanding clinically silent infection. Newly acquired genital herpes can cause a prolonged clinical illness with severe genital ulcerations and neurologic involvement. Persons with HSV-1 antibodies often have oral HSV infection acquired during childhood, which might be asymptomatic. Lack of symptoms in a person who is HSV-1 seropositive does not distinguish anogenital from orolabial or cutaneous infection, and, regardless of site of infection, these persons remain at risk for acquiring HSV-2. Therefore, in cases of recent suspected HSV-2 acquisition, repeat type-specific antibody testing 12 weeks after the presumed time of acquisition is indicated. Immunoglobulin M (IgM) testing for HSV-1 or HSV-2 is not useful because IgM tests are not type specific and might be positive during recurrent genital or oral episodes of herpes Therefore, HSV IgM testing is not recommended. The most commonly used test, HerpeSelect HSV-2 enzyme immunoassay (EIA), often is falsely positive at low index values (1.1–3.0) One study reported an overall specificity of 57.4%, with a specificity of 39.8% for index values of 1.1–2.9 Because of the poor specificity of commercially available type-specific EIAs, particularly with low index values (<3.0), a confirmatory test (Biokit or Western blot) with a second method should be performed before test interpretation. However, these drugs neither eradicate latent virus nor affect the risk, frequency, or severity of recurrences after the drug is discontinued. Sensitivity 80% to 98%. false-negative results might be more frequent at early stages of infection. HSV-2 estimate 11.9% of persons aged 14–49 years are estimated to be infected in the United States, NHANES 2015 to 2016. Last Reviewed: September 21, 2022. Read 2026-09-28.
- CDC, MMWR, HSV-2 seroprevalence among persons aged 14 to 49, United States, 2005 to 2008. Of those testing positive for HSV-2 infection, 81.1% said they had never been told by a doctor or health-care professional that they had genital herpes. Page last reviewed: April 23, 2010. Read 2026-09-28.
- National Center for Health Statistics, Data Brief No. 304. Herpes simplex virus types 1 and 2 (HSV-1 and HSV-2) are common, lifelong infections, which often have no symptoms. HSV-2 estimate for persons aged 14 to 49 in the United States, NHANES 2015 to 2016: 11.9% of persons aged 14–49 years are estimated to be infected in the United States. Last Reviewed: February 7, 2018. Read 2026-09-28.
- World Health Organization, Herpes simplex virus. Most HSV infections are asymptomatic or unrecognized, but symptoms of herpes include painful blisters or ulcers that can recur over time. Many people aren't aware they have the infection and can pass along the virus to others without knowing. Herpes simplex virus lives inside of nerve cells and alternates between being inactive and active. HSV-2 can be transmitted even if the skin looks normal and is often transmitted in the absence of symptoms. Medicines are often used to treat first or recurrent symptomatic episodes (outbreaks) of herpes. They can decrease how long symptoms last and how severe they are, but they can’t cure the infection. Fact sheet 30 May 2025. Read 2026-09-28.
- MedlinePlus, Genital herpes. Sometimes people do not know they have herpes because they have no symptoms or very mild symptoms. The virus stays in your body for life. Last updated May 31, 2024. Read 2026-09-28.
- MedlinePlus Medical Encyclopedia, Genital herpes. Many people with genital herpes never have sores. Or they have very mild symptoms that go unnoticed or are mistaken for insect bites or another skin condition. This first outbreak most often happens within 2 days to 2 weeks of being infected. A positive test result when a person has never had an outbreak would indicate exposure to the virus at some time in the past. Some people never have another episode. Review Date 7/3/2025. Read 2026-09-28.
- Office on Women's Health, Genital herpes. Most women with genital herpes do not know they have it. The first signs of genital herpes usually show up two to 12 days after having sexual contact with someone who has herpes. Even though you may not have a genital herpes outbreak for long periods of time, you can still pass the virus to another person at any time. Page last updated: January 6, 2023. Read 2026-09-28.
- ACOG, Why does herpes cause repeated outbreaks?. After a person is first infected, the herpes virus travels to nerve cells near the spine and stays there. When there is a trigger, the virus can become active again. Triggers can include illness, stress, and hormonal changes. Last reviewed: September 2021. Read 2026-09-28.
- American Sexual Health Association, Fast facts about HSV. A person may show symptoms within days after contracting genital herpes, or it may take weeks, months, or years. In the ganglion, the virus remains inactive (“latent”) for an indefinite period of time. Then researchers learned that the virus could wake and become active without causing noticeable signs or symptoms: no itch, no pain, no pimples, no blisters. For this reason, it can be difficult for people to know when and from whom they may have contracted the virus. Read 2026-09-28.
- American Sexual Health Association, Herpes testing. Blood tests do not actually detect the virus; instead, they look for antibodies (the body's immune response) in the blood. IgG appears soon after infection and stays in the blood for life. For this reason, we do not recommend using blood tests as a way to determine how long a person has had herpes. Unfortunately, most people who are diagnosed will not be able to determine how long they have had the infection. Some assume that if a test discovers IgM antibodies, the infection is new. But research has shown this is not the case. IgM can appear in blood tests in up to a third of people during recurrences (outbreaks) in people who have been infected for some time. For the most accurate test result, it is recommended to wait 12 – 16 weeks from the last possible date of exposure before getting an accurate, type-specific blood test in order to allow enough time for antibodies to reach detectable levels. Read 2026-09-28.
- American Sexual Health Association, Herpes and relationships. Remember, if you have been sexually active you may already have been exposed to herpes. You may have it and not know it. Because herpes can be spread without symptoms (asymptomatic shedding) it can be hard to know when a person became infected and who infected them. In fact, if you and your partner have had sex, it's possible your partner got herpes from you. Read 2026-09-28.