Medically reviewed by Michele Emery, DNP
Written by Our Editorial Team
Last updated 4/17/2020
Are you worried you might have been exposed to the herpes virus?
First: don't panic. The HSV viruses are a lot more common than you may think, and are very manageable in most cases.
Second: if you think you’ve been exposed to the herpes virus, testing is going to be your first plan of action.
Take a couple deep breaths and when you're ready, read on.
Herpes is highly contagious and common, affecting an estimated 67 percent of people under the age of 50 worldwide in the form of HSV-1, and 11 percent of people ages 15 to 49 as HSV-2.
Many people with herpes aren’t aware that they have the virus. While some people with oral or genital herpes experience occasional outbreaks, many others can be asymptomatic, meaning they’re carrying the virus but don’t have any noticeable symptoms.
This means that you can potentially catch herpes from someone with symptoms of the virus, all without experiencing any symptoms yourself. Or, perhaps worse, you can potentially catch herpes from someone who isn’t exhibited any symptoms whatsoever.
Luckily, a variety of tests are available to check for herpes. Today, the most common tests used to detect herpes are PCR blood tests, herpes antibody blood tests and viral culture tests. Your healthcare provider will determine what is the right test for your symptoms.
Each type of herpes test has advantages and disadvantages. Below, we’ve explained the tests in more detail, with specific information on the best options for getting real, reliable information about whether or not you have herpes.
The best time to get tested for herpes varies, depending on what's happening.
If you're exhibiting symptoms of an initial outbreak — which include pain, itching and redness of the affected location; fatigue, fever and chills (similar to the flu); and, ultimately, painful sores or ulcers — it's best to see a healthcare professional about getting tested.
However, if you think you've been exposed to the virus and aren't yet exhibiting symptoms, HSV may take some time before being able to show results on a test. While the exact time frame is unknown and varies from person to person, two weeks is usually enough time to yield accurate test results.
Most people become concerned about being infected with the herpes virus after contact with a potentially infected person. Often, simple things like kissing someone with a visible cold sore or facial acne around the lips can cause concern about HSV-1.
For genital herpes, most people become concerned about potentially being infected after sexual contact with a person that shows symptoms of herpes. This can include oral sex with someone that has cold sores, which can potentially spread to the genitals.
Since herpes is asymptomatic in many people, you could be infected with the virus even if you don’t have any symptoms.
A common type of herpes test is a viral culture test. To perform a viral culture test, your healthcare provider will extract a small amount of skin cells from the part of your body they believe is infected by the virus. This is typically your lips, mouth or the area around your genitals and/or anus.
Your healthcare provider will only need to take a tiny cellular sample in order to administer the test. Typically, this is collected by collecting fluid from the skin lesion with a cotton swab. The process is fast, simple and only involves minor discomfort for most people.
After your healthcare provider has extracted a cellular sample, it’s sent to a laboratory for analysis. Using a microscope, scientists will monitor the growth of the virus in a lab culture over a period of several days to find out if the cellular sample is infected.
A viral culture test usually takes two to five days to produce a reliable result. The results of the test will depend on the activity of your sample. If the scientists notice the virus growing, they’ll mark the test as positive; if not, it will be marked as negative.
Viral culture tests are very accurate at detecting herpes infections. However, they also have a major weakness. Since this form of testing requires the virus to be active in a sore or lesion, it can’t be reliably used to detect asymptomatic cases of herpes.
In short, viral culture tests are great for confirming you have herpes if you already have oral or genital herpes symptoms, but you can’t rely on them if you’re worried about potentially having an asymptomatic infection.
Luckily, there are tests available to check for asymptomatic herpes. Today, the most accurate test for asymptomatic herpes infections is a blood test. This blood test, called a serum antibody test, can detect both HSV-1 and HSV-2 viruses.
After you become infected with herpes, your body fights back against the virus by producing antibodies. These antibodies act like ammunition for your body as it works to contain bacteria and viruses such as HSV-1 and HSV-2.
The body produces two antibodies in response to a herpes infection — IgG and IgM. Both of these antibodies can be detected using a blood test, although there are some limitations that can affect the accuracy and efficacy of this form of testing.
IgM antibodies are usually detectable for the initial seven to 10 days after you become infected with HSV-1 or HSV-2. For most people, this period coincides with the initial outbreak period of the virus, during which symptoms can be intense and obvious.
The levels of IgM in your bloodstream usually increase for around two weeks after infection, before declining as the initial outbreak passes. IgM antibodies are detectable even if you’re asymptomatic, meaning you don’t need to have herpes symptoms to take this test.
If you believe you’re experiencing an initial herpes outbreak or have concerns that you might have recently been exposed to herpes through oral or sexual contact, you may want to talk to your healthcare provider about IgM testing.
The second type of herpes antibody test is an IgG test. IgG antibodies usually take longer to show up in your bloodstream after a herpes infection. Instead, they’re produced more slowly after the infection has “set in” and your body’s immune system is actively responding.This means you can test for IgG antibodies for a longer period than IgM antibodies.
IgG tests can also distinguish between the two most common types of herpes, HSV-1 and HSV-2. This makes IgG antibody testing ideal for detecting asymptomatic, latent herpes infections.
Despite being able to provide type-specific information on HSV-1 and HSV-2, antibody testing can’t differentiate between oral and genital herpes. Instead, you’ll receive a clear “yes” or “no” answer on the presence of specific herpes antibodies, such as HSV-1 or HSV-2.
While herpes blood test accuracy isn't down to a perfect science, it's still a very reliable way to find out whether or not you're a carrier of the virus.
Unfortunately, antibody tests can also occasionally lead to false results. Herpes blood test false negatives and false positives do happen and, unfortunately, they're oftentimes not clearly communicated by healthcare professionals to their patients.
Because of this, you may want to schedule several herpes tests over a period of months to be completely certain that you are or are not infected. Herpes testing results only become more definitive the more times you take them.
The third form of herpes testing in use today is a polymerase chain reaction (PCR) test. This type of test involves searching for and detecting the specific genetic material (DNA) that makes up the herpes simplex virus.
PCR tests can be used to detect the presence of herpes, and to differentiate between infections of HSV-1 and HSV-2. To carry out a PCR test, your healthcare provider will take a sample from a lip or genital sore that you believe is a result from the virus, typically in the form of a swab.
The sample is then tested for DNA that resembles HSV-1 or HSV-2, allowing testers to look for the virus on a genetic level.
Compared to viral culture and antibody testing, both of which can require several days before an accurate result is available, PCR testing is fast and efficient.
PCR tests also allow for testing much later into an outbreak than viral culture testing, which can often result in a false negative result when the herpes virus is no longer actively growing on the sample cells.
Because the PCR test requires a sample of the infected area, it’s typically used for symptomatic herpes infections that produce genital lesions or cold sores. However, it’s also possible to carry out a PCR test using blood, spinal fluid and other types of cell samples.
This makes PCR testing a good option if you’ve previously experienced herpes outbreaks but don’t have any visible symptoms when you choose to get tested. Using blood or spinal fluid, a testing lab can look for genes from HSV-1 and HSV-2 even without any physical symptoms.
Each method of testing for herpes has advantages and disadvantages, from time and cost, to an increased possibility of false results. Often, people concerned about the virus use a range of herpes testing to get a more accurate, proven picture of whether or not they’re infected with HSV-1 or HSV-2.
Since herpes is a lifelong infection that can’t be cured, it’s important to discuss testing options with your healthcare provider and make sure you receive an accurate result. Your healthcare provider will be able to tell you more about the best options for herpes testing based on your symptoms and situation.
Typically, your healthcare provider will carry out a physical exam before choosing the best testing method for you. As herpes symptoms tend to be worst during the initial outbreak of the virus, it’s best to talk to your healthcare provider as soon as you start experiencing symptoms.
In the event that you do have herpes, there’s no need to panic. Both oral and genital herpes are extremely common, and a variety of effective treatments are available for both.
Our Valacyclovir 101 guide goes into more detail about one of the most common, effective drugs for treating both symptomatic and asymptomatic herpes. You can also learn more about the risk of catching herpes in our guide to how herpes is transmitted between people.