There are eight types of herpes that infect humans, officially labeled Human Herpesvirus 1 through 8 (HHV-1 through HHV-8). Most people only think of cold sores and genital herpes, but the herpes family also includes the viruses behind chickenpox, mono, and several cancers. All eight share one defining trait: once you’re infected, the virus stays in your body for life, hiding in specific cells and occasionally reactivating.
HSV-1: Oral Herpes
Herpes simplex virus type 1 is the most common of all human herpesviruses and the one behind cold sores. It spreads through contact with sores, saliva, or skin around the mouth. Most people pick it up in childhood from a kiss or shared utensil, and the majority never develop noticeable symptoms.
When symptoms do appear, they typically start with tingling, itching, or burning near the lips, followed by blisters or open sores in or around the mouth. A first outbreak can also bring fever, body aches, and swollen lymph nodes. After the initial infection clears, HSV-1 travels up nerve fibers and settles into sensory nerve cells near the base of the skull, where it stays dormant. Stress, illness, or sun exposure can trigger reactivation, sending the virus back down the nerve to produce a new cold sore.
HSV-1 can also cause genital herpes when transmitted through oral sex. Genital HSV-1 infections tend to recur far less often than genital HSV-2 infections. Asymptomatic shedding, meaning the virus is present on the skin with no visible sore, is relatively common in the first months after infection (about 12% of days) but drops to around 7% of days by 11 months and can fall below 2% after two years.
HSV-2: Genital Herpes
Herpes simplex virus type 2 spreads primarily through sexual contact with genital or anal skin, sores, or fluids. It causes bumps, blisters, or open ulcers around the genitals or anus. Like HSV-1, it hides in sensory nerve ganglia after the first infection and can reactivate repeatedly.
The key difference from HSV-1 is recurrence rate. HSV-2 is much more likely to cause repeated outbreaks, and it sheds asymptomatically far more often: about 34% of days in the first year and still around 17% of days a decade later. That high shedding rate is why transmission can happen even when no sores are visible. Antiviral medication taken daily can reduce both outbreaks and the risk of passing the virus to a partner.
Varicella-Zoster Virus (HHV-3)
This is the virus behind two distinct illnesses at different stages of life. The first infection causes chickenpox, typically in childhood, with its characteristic itchy, blister-like rash all over the body. After chickenpox resolves, the virus retreats into sensory nerve cells along the spine and stays dormant, sometimes for decades.
When it reactivates, it causes shingles: a painful, blistering rash that usually appears in a band on one side of the torso, though it can affect the face or eyes. Shingles becomes more common with age and in people with weakened immune systems. A vaccine is available for both chickenpox (given in childhood) and shingles (recommended for adults 50 and older).
Epstein-Barr Virus (HHV-4)
Epstein-Barr virus is best known as the cause of infectious mononucleosis, or “mono.” Symptoms include extreme fatigue, fever, sore throat, swollen lymph nodes, and an enlarged spleen. It spreads through saliva, which is why mono is sometimes called the “kissing disease.” Most people are infected by adulthood, though many never realize it because the infection can be mild or symptom-free, especially in young children.
What makes EBV notable beyond mono is its link to several cancers. It plays a role in certain lymphomas, including Burkitt lymphoma and Hodgkin lymphoma, as well as nasopharyngeal and gastric cancers. More recently, large-scale studies have connected EBV infection to a significantly increased risk of developing multiple sclerosis. In people with healthy immune systems, these complications are rare. The virus persists in a type of white blood cell and occasionally reactivates, though most people never notice.
Cytomegalovirus (HHV-5)
Cytomegalovirus, or CMV, infects the majority of adults worldwide, and most have no idea. In healthy people, a CMV infection either causes no symptoms or looks like a mild case of mono: fatigue, fever, and muscle aches. It can sometimes be confused with EBV-related mono, and doctors often test for CMV when the standard mono blood test comes back negative.
CMV poses its greatest risk in two situations. During pregnancy, a primary CMV infection can be passed to the fetus, potentially causing hearing loss, developmental delays, or other serious problems at birth. And in people with weakened immune systems, such as organ transplant recipients or those living with advanced HIV, CMV can attack the eyes, lungs, liver, or digestive tract.
HHV-6 and HHV-7: The Roseola Viruses
These two closely related viruses are responsible for roseola, one of the most common childhood illnesses. Roseola typically strikes between 6 and 15 months of age. It begins with a sudden high fever, often above 103°F (39.4°C), lasting three to five days. Some children also develop a sore throat, runny nose, irritability, or mild diarrhea. Then, just as the fever breaks, a distinctive rash appears: flat pink spots that start on the chest, back, and belly before spreading to the neck, arms, and sometimes the face and legs.
HHV-6 is the more common cause; HHV-7 can cause a similar illness or trigger reactivation of HHV-6. For most children, roseola resolves on its own within a week. In rare cases, particularly in immunocompromised individuals, HHV-6 can cause encephalitis (inflammation of the brain).
HHV-8: Kaposi Sarcoma Herpesvirus
Human herpesvirus 8 stands apart from the others because it doesn’t cause an obvious acute illness in most people. Instead, it’s defined by its connection to cancer. HHV-8 is the direct cause of all forms of Kaposi sarcoma, a cancer that produces dark, purplish skin lesions and can also affect the mouth, lungs, and digestive tract. There are four recognized forms: classic (typically in older men of Mediterranean or Eastern European descent), endemic (in sub-Saharan Africa), transplant-associated, and HIV-associated, which was one of the earliest recognized signs of the AIDS epidemic.
Beyond Kaposi sarcoma, HHV-8 is linked to primary effusion lymphoma, a rare cancer that grows in fluid-filled body cavities, and to a form of multicentric Castleman disease, a condition involving overgrowth of lymph node tissue. Nearly all of these complications occur in people with suppressed immune systems.
What All Eight Types Share
Every human herpesvirus establishes lifelong latency. The specific hiding spot varies by virus type: HSV-1, HSV-2, and varicella-zoster settle into sensory nerve cells, while EBV lurks in immune cells and CMV can persist in several cell types. This is why “curing” herpes isn’t currently possible. Antiviral medications can suppress replication and reduce symptoms, but they don’t eliminate the dormant virus from its hiding place.
Reactivation can be triggered by stress, illness, immune suppression, or sometimes nothing identifiable at all. For most of the eight types, reactivation in a healthy person is either symptom-free or mild. The serious complications, from shingles to CMV retinitis to Kaposi sarcoma, tend to emerge when the immune system is weakened by age, medication, or disease.