Herpes is a general term for two different diseases: one that effects the area around the mouth (oral herpes, also known as cold sores) and another that effects the area around the genitals (genital herpes). Viruses cause both of these diseases. The herpes simplex virus-1 (HSV-1) causes oral herpes; both HSV-1 and herpes simplex virus-2 (HSV-2) cause genital herpes. While HSV-1 and HSV-2 are different viruses, they look very much the same and are treated similarly.
Herpes cannot be cured. Once someone is infected with either virus, it cannot be cleared from the human body.
Both HSV-1 and HSV-2 live in nerve cells, usually under the skin. Neither virus is always active. They often remain silent or inactive in these cells, sometimes for many years or even a lifetime. This is called "latency." For reasons not entirely understood by researchers, the viruses can become active and cause symptoms, which include sores around the mouth or near the genitals. This is called "reactivation." These symptoms can come and go in what is known as outbreaks, or "flare-ups."
During a flare-up, the virus becomes active and causes a chain of events leading to a cluster of small bumps to form. The bumps may rupture, heal, and then disappear for an indefinite period of time.
Anyone infected with either virus, regardless of their HIV status, can experience oral or genital herpes flare-ups. Approximately 70% of all adults living in the United States are infected with one—or both—viruses. HSV-1 is spread via direct contact with an infected area, usually during a flare-up of the disease. Kissing and oral-genital sex can spread HSV-1. More serious sexual activity, including penile-vaginal or penile-anal intercourse, is the main route by which HSV-2 is spread. Both types of HSV can actively reproduce without causing symptoms, this is known as viral "shedding." A person with HSV can infect another person when they are shedding, even if they do not currently have any sores.
Anybody infected with either virus can experience flare-ups. In people who have healthy immune systems, a herpes flare-up usually lasts a few weeks. In people with compromised immune systems, including people with HIV and AIDS, the herpes sores can last longer than a month. Severe herpes flare-ups can be incredibly painful. In a very small number of cases, herpes can spread to other organs, including the eyes, the throat, the lungs, and the brain.