There are eight types of herpes viruses that infect humans, numbered Human Herpesvirus 1 through 8 (HHV-1 through HHV-8). Most people only think of cold sores or genital herpes, but the herpes family also includes the viruses behind chickenpox, mono, and several other conditions. All eight share a defining trait: once they infect you, they stay in your body for life, alternating between dormant and active phases.
The Eight Human Herpesviruses at a Glance
Each type has both a common name and a formal HHV number. Here’s the full list:
- HHV-1: Herpes simplex virus type 1 (HSV-1), oral herpes
- HHV-2: Herpes simplex virus type 2 (HSV-2), genital herpes
- HHV-3: Varicella-zoster virus (VZV), chickenpox and shingles
- HHV-4: Epstein-Barr virus (EBV), mononucleosis
- HHV-5: Cytomegalovirus (CMV)
- HHV-6A and HHV-6B: Associated with roseola in infants
- HHV-7: Also linked to roseola
- HHV-8: Kaposi sarcoma-associated herpesvirus (KSHV)
The first three are the ones most people recognize because they cause visible sores on the skin. The remaining five tend to affect internal organs or the immune system and often go unnoticed in healthy individuals.
HSV-1 and HSV-2: The “Classic” Herpes Types
When people say “herpes” without further context, they almost always mean one of these two. HSV-1 causes infections in or around the mouth, commonly called cold sores or fever blisters. It spreads mainly through contact with sores, saliva, or skin surfaces near the mouth. HSV-1 can also cause genital herpes when transmitted through oral-genital contact, though this is less common.
HSV-2 is the primary cause of genital herpes. It spreads during sex through contact with genital or anal skin, sores, or fluids, and it can transmit even when the skin looks completely normal. HSV-2 infects women nearly twice as often as men because sexual transmission is more efficient from men to women. It also causes more frequent outbreaks than genital HSV-1 infections do.
Both viruses live inside nerve cells and cycle between inactive and active states. In rare cases, either type can pass from mother to child during delivery, causing neonatal herpes.
Varicella-Zoster Virus (HHV-3)
This is the virus behind chickenpox. After the initial infection clears, the virus doesn’t leave. It hides in sensory nerve clusters near the spine and can reactivate decades later as shingles, a painful blistering rash that typically appears on one side of the body. The older you get and the weaker your immune system becomes, the higher your risk of reactivation. Vaccines exist for both chickenpox and shingles, making HHV-3 the most preventable member of the herpes family.
Epstein-Barr Virus (HHV-4)
Epstein-Barr virus is best known for causing infectious mononucleosis, often called “mono” or “the kissing disease.” Symptoms include swollen lymph nodes, an enlarged spleen, sore throat, and extreme fatigue. Compared to the simplex viruses, EBV rarely produces visible sores on the skin. Instead, it targets immune cells called B lymphocytes and establishes a lifelong latent infection in them.
Most people contract EBV at some point in their lives, often during childhood when the infection tends to be mild or symptomless. When it hits in the teenage or young adult years, it’s more likely to cause the full-blown mono syndrome. Cervical lymph node swelling, sore throat, and enlarged liver or spleen are hallmarks that help distinguish it from other infections.
Cytomegalovirus (HHV-5)
Cytomegalovirus is remarkably common and almost always silent. In healthy people, a primary CMV infection is either asymptomatic or produces mild flu-like symptoms. When symptoms do appear, they develop anywhere from 9 to 60 days after infection and can include swollen lymph nodes, an enlarged spleen, and lingering fatigue that sometimes persists long after lab results look normal.
CMV can produce a mononucleosis-like illness that mimics EBV. The two look similar on the surface, though CMV mono tends to show up in slightly older patients, lasts longer, and involves less throat pain and lymph node swelling than EBV mono. The real danger of CMV comes when the immune system is compromised. In people with advanced HIV or those on immunosuppressive medications after organ transplants, CMV can cause serious problems in the lungs, liver, digestive tract, and eyes.
HHV-6, HHV-7, and HHV-8
These three get far less attention than their relatives, but they’re worth knowing about. HHV-6 actually comes in two subtypes, 6A and 6B, and HHV-6B is the main cause of roseola infantum, a common childhood illness marked by a few days of high fever followed by a distinctive pink rash. HHV-7 is closely related and also associated with roseola. Nearly all children contract HHV-6 and HHV-7 before the age of three, often without their parents realizing it’s a herpesvirus at work.
HHV-8 is the rarest and most dangerous of the group. It causes all forms of Kaposi sarcoma, a cancer that produces dark skin lesions and can affect internal organs. HHV-8 is also linked to primary effusion lymphoma and a form of Castleman’s disease, both of which involve abnormal growth of immune cells. These conditions are most common in people with weakened immune systems, particularly those living with HIV.
Why All Eight Types Share the Same Family
Despite causing wildly different diseases, all eight viruses share a core behavior: latency. After the initial infection, each virus retreats into specific cell types and goes dormant. HSV-1 and HSV-2 hide in nerve cells near the spine. Varicella-zoster tucks itself into sensory nerve clusters. EBV camps out in immune cells. This ability to persist indefinitely is what defines the herpesvirus family and why none of these infections can be fully cured. Antiviral medications can reduce symptoms and lower the frequency of outbreaks, but they cannot eliminate the dormant virus.
How Herpes Types Are Identified
If you have visible sores, a healthcare provider can swab the fluid and run one of two tests. A viral culture grows cells from the sample in a lab and then checks for the virus, but this takes time. A PCR test looks for the virus’s genetic material directly and is both faster and more accurate. If there are no active sores, a blood test can detect antibodies your immune system made in response to the virus. Antibody tests can distinguish between HSV-1 and HSV-2 specifically, which matters because the two types differ in how often they reactivate and how they’re managed.
For the other herpesviruses, testing is typically only done when symptoms suggest a specific condition or when someone is immunocompromised. Most healthy adults carry several of these viruses without ever needing a diagnosis.
Treatment for Herpes Infections
Three antiviral medications are approved for treating herpes simplex infections: acyclovir, valacyclovir, and famciclovir. For a first genital herpes outbreak, treatment typically runs 7 to 10 days. People with frequent recurrences can take daily suppressive therapy to reduce the number of outbreaks and lower the risk of transmitting the virus to a partner. These medications work by interfering with the virus’s ability to copy itself, which shortens outbreaks and eases symptoms but does not eliminate the latent virus.
For varicella-zoster, the same class of antivirals is used to treat shingles, and vaccines offer strong prevention. EBV and CMV infections in healthy people generally don’t require treatment beyond rest and symptom management. HHV-8-related cancers are treated with approaches specific to the type of cancer involved.