HSV-1+ means you tested positive for herpes simplex virus type 1, the virus responsible for most cold sores. An estimated 3.8 billion people under age 50 globally, roughly 64% of the population, carry this same virus. A positive result tells you that your immune system has encountered HSV-1 at some point, but it doesn’t tell you when you were infected or whether you’ll ever have symptoms.
What a Positive Test Result Means
Most HSV-1 testing looks for IgG antibodies in your blood. These are proteins your immune system produces after exposure to a virus, and they stick around permanently. A positive IgG result indicates past exposure and immunity, not necessarily an active infection happening right now. A separate type of antibody, IgM, can indicate a recent or new infection, but IgM testing for herpes is less reliable and not routinely recommended.
Lab results typically report an antibody index value. For HSV-1 IgG, a result below 0.9 is considered non-reactive (negative), 0.9 to 1.0 is equivocal (borderline), and anything above 1.1 is reactive (positive). If your result falls in the equivocal range, retesting in a few weeks can clarify things. A single IgG level is not useful for diagnosing an active outbreak on its own.
How Most People Get HSV-1
HSV-1 spreads primarily through direct contact with an infected person’s skin or saliva. Many people are infected during childhood through casual contact like a kiss from a family member. The virus can also spread from the mouth to a partner’s genitals during oral sex, which is why genital HSV-1 infections have become increasingly common.
The virus sheds even when no sores are visible. Research from the University of Washington found that people with genital HSV-1 shed the virus on about 12% of days in the first two months after infection, dropping to 7% of days by 11 months. Over longer periods, shedding fell even further, to about 1.3% of days. In most of those instances, participants had no symptoms at all while shedding.
Symptoms You Might Experience
Many people with HSV-1 never develop noticeable symptoms. When symptoms do appear, they typically show up as cold sores or fever blisters on or around the mouth. A first outbreak can also include flu-like symptoms: fever, body aches, and swollen glands. Subsequent outbreaks tend to be milder and shorter.
If HSV-1 infects the genital area, the initial episode looks similar: one or more blisters on or around the genitals or rectum, sometimes with systemic symptoms. The key difference is what happens afterward. Genital HSV-1 recurs far less often than genital HSV-2. The average person with genital HSV-2 has four to five outbreaks per year. The average for genital HSV-1 is less than one per year. Many people have a single episode and never have another.
Why You Might Not Have Been Tested Before
If you’re surprised by this result, you’re not alone. The CDC does not recommend routine herpes blood testing for people without symptoms. The reasoning is that blood tests have limits, and the chance of a misleading result is higher in people at low risk of infection. Most people who test positive for HSV-1 were tested because they specifically requested it, because a provider was investigating symptoms, or because it was included in a broader panel they ordered.
Treatment and Outbreak Management
There is no cure for HSV-1, but the virus is manageable. Antiviral medications can shorten outbreaks and reduce their severity. For a first genital outbreak, a typical course of treatment lasts 7 to 10 days and can be extended if healing is slow.
For oral HSV-1 (cold sores), many people use antiviral treatment only when they feel an outbreak starting. The earlier you take it, the more effective it tends to be. Some people recognize a tingling or burning sensation at the site before blisters appear, which is the ideal time to start medication.
Daily suppressive therapy, where you take an antiviral every day to prevent outbreaks, is generally reserved for people who experience frequent recurrences. Because genital HSV-1 recurs so infrequently on average, most people with that diagnosis don’t need daily medication.
Reducing Transmission Risk
If you have oral HSV-1, avoiding kissing and sharing utensils during an active cold sore reduces the risk of spreading it. Oral sex during an active outbreak can transmit HSV-1 to a partner’s genitals, so abstaining from oral contact when sores are present is the most straightforward precaution.
Because asymptomatic shedding happens, transmission is possible even without visible sores, though the risk is lower. Shedding frequency decreases significantly over time, which means the longer you’ve carried the virus, the less often you’re likely shedding it. For people in relationships where one partner is positive and the other is not, antiviral medication and barrier methods both reduce transmission risk further.
Living With HSV-1
A positive HSV-1 result can feel alarming, but the reality is that the majority of adults worldwide carry this virus. Most experience mild or no symptoms, and for those who do have outbreaks, frequency tends to decrease over the years. The virus stays in your body permanently, residing in nerve cells in a dormant state between outbreaks, but it rarely causes serious complications in healthy adults.
Stress, illness, sun exposure, and fatigue are common triggers that can reactivate the virus. Paying attention to your personal triggers can help you anticipate and manage outbreaks more effectively.