There are eight types of herpes that infect humans, each caused by a distinct virus in the herpesvirus family. Most people only think of cold sores and genital herpes, but the herpes family also includes the viruses behind chickenpox, shingles, mono, and several other conditions. Every one of these viruses shares a defining trait: once you’re infected, the virus stays in your body for life and can reactivate later.
HSV-1: Oral Herpes
Herpes simplex virus type 1 is the most common herpesvirus worldwide. It spreads through contact with sores, saliva, or skin surfaces in and around the mouth, and it’s the virus behind cold sores. Most people pick it up during childhood from a kiss or shared utensil, often without ever knowing it.
HSV-1 can also cause genital herpes when transmitted through oral sex, which has become increasingly common. Even when no sores are visible, the virus can shed from skin and saliva. PCR testing, which detects the virus’s genetic material, has found HSV-1 DNA present on about a third of days tested in people carrying the virus. That shedding rate varies enormously from person to person, ranging from essentially zero to over 90% of days.
HSV-2: Genital Herpes
Herpes simplex virus type 2 spreads mainly through sexual contact with genital or anal surfaces, skin, sores, or fluids. It causes genital herpes almost exclusively, producing recurring outbreaks of blisters or sores in the genital and anal area. Outbreaks tend to be more frequent with HSV-2 than with genital infections caused by HSV-1.
Many people with HSV-2 have mild or no symptoms, which is one reason the virus spreads so easily. It can shed from the skin between outbreaks with no visible signs. If you have active sores, a swab test (PCR) is the fastest and most accurate way to confirm the diagnosis. Without sores, a blood test can look for antibodies, though it takes up to three months after infection for your body to produce enough antibodies to be detected.
HHV-3: Varicella-Zoster Virus
This is the virus behind two familiar illnesses: chickenpox in childhood and shingles later in life. After a chickenpox infection clears, the virus doesn’t leave your body. It goes dormant in nerve clusters along the spine called dorsal root ganglia, where it can sit quietly for decades.
When the virus reactivates, typically due to aging, stress, or a weakened immune system, it travels along a nerve to the skin and causes shingles. Shingles produces a painful, blistering rash that usually appears in a band on one side of the body. The pain can linger for months or even years after the rash heals, a complication known as postherpetic neuralgia. Vaccines are available for both chickenpox and shingles.
HHV-4: Epstein-Barr Virus
Epstein-Barr virus (EBV) is best known as the cause of infectious mononucleosis, or “mono,” the illness sometimes called the kissing disease. It spreads through saliva and is extremely widespread. Most people are infected at some point in their lives, often during adolescence or young adulthood, when symptoms are most noticeable: severe fatigue, sore throat, swollen lymph nodes, and fever that can last weeks.
What makes EBV stand out from the other herpesviruses is the range of serious conditions linked to it. EBV infection is associated with several cancers, including Burkitt’s lymphoma, Hodgkin’s disease, non-Hodgkin’s lymphoma, and nasopharyngeal carcinoma (a cancer of the upper throat). These outcomes are rare compared to the vast number of people carrying EBV, but the connection is well established. The virus can also affect the nervous system, contributing to conditions like meningitis, encephalitis, and facial nerve paralysis, and has been linked to heart muscle inflammation and lung disease.
HHV-5: Cytomegalovirus
Cytomegalovirus (CMV) is another herpesvirus that most people carry without knowing it. In healthy adults, initial infection may cause mild, flu-like symptoms or no symptoms at all. The virus spreads through bodily fluids like saliva, urine, breast milk, and blood.
CMV becomes a serious concern in two situations. For people with weakened immune systems, such as organ transplant recipients or those with HIV, CMV reactivation can damage the eyes, lungs, liver, and digestive tract. The other major risk is during pregnancy: if a mother is infected with CMV for the first time while pregnant, the virus can pass to the developing baby and cause hearing loss, vision problems, or developmental delays.
HHV-6 and HHV-7: Roseola and Beyond
Nearly every child encounters HHV-6 and HHV-7 in their first few years of life. HHV-6B is the cause of roseola (sometimes called sixth disease), the common childhood illness marked by a few days of high fever followed by a pinkish rash that appears as the fever breaks. It resolves on its own and rarely causes lasting problems in healthy children.
In adults with compromised immune systems, HHV-6 tells a different story. It’s a major cause of opportunistic infections in transplant recipients and people with AIDS, where reactivation can contribute to organ rejection and other serious complications. Researchers have also explored a possible link between HHV-6 and multiple sclerosis, though that connection is still being studied. HHV-7 is closely related and can reactivate alongside HHV-6 or CMV in transplant patients, though it causes fewer recognized problems on its own.
HHV-8: Kaposi’s Sarcoma Virus
The eighth human herpesvirus is also called Kaposi’s sarcoma-associated herpesvirus. It causes Kaposi’s sarcoma, a cancer that forms in the lining of blood and lymph vessels and appears as purple, red, or brown lesions on the skin or inside the mouth, lungs, or digestive tract. Before the HIV/AIDS epidemic, Kaposi’s sarcoma was rare. It became one of the defining illnesses of AIDS in the 1980s and remains most common in people with significantly weakened immune systems.
What All Herpesviruses Share
Despite causing very different diseases, all eight human herpesviruses follow the same basic playbook. They establish a lifelong infection by hiding inside specific cells, whether nerve cells (HSV-1, HSV-2, varicella-zoster) or immune cells (EBV, CMV, HHV-6, HHV-7, HHV-8). The virus can stay dormant for years and reactivate when conditions are right, often when the immune system is under stress.
There is no cure for any herpesvirus. Antiviral medications can reduce the frequency and severity of outbreaks for HSV-1, HSV-2, and varicella-zoster, and can help manage CMV in high-risk patients. But none of these treatments eliminate the virus from the body. Vaccine development is active, with an mRNA-based vaccine candidate for HSV-2 currently in early-phase clinical trials, though nothing is close to widespread availability yet.
If you’re getting tested, the method matters. For active sores or blisters, a PCR swab is faster and more accurate than a traditional viral culture. For infections without visible symptoms, a blood test that checks for antibodies can confirm past or present infection, but timing is important. Antibodies may not show up for up to three months after initial infection, so an early test can come back negative even when the virus is present.