Because infection by HSV-1 (Herpes simplex virus -1) usually occurs early in life through asymptomatic infection of the mouth and throat, this means that a high proportion of the population carry the virus in its latent form. Herpes simplex 1 and 2 viruses are similar in that they are both transmitted by direct contact and can sometimes cause intensely painful fluid-filled blisters, containing millions of infectious virus particles. To achieve an initial infection, the following conditions must apply: the herpes simplex requires transportation in bodily fluids (saliva, semen, fluid in the female genital tract) or in fluid from herpes sores. The lesions of both types of herpes can be spread by touching an unaffected part of the body immediately after touching a herpes lesion.

A majority of people have been exposed to herpes simplex virus without being aware of it, usually sometime in early childhood. Preventing the virus is difficult since people can spread it even when they don't have any symptoms of an active outbreak. Because the chances of contracting this disease increase with the number of sexual partners a person has, limiting the number of partners is the first step toward prevention. When one partner has herpes simplex infection and the other does not, the use of a condom has been demonstrated to decrease the chances of transmission to the uninfected partner.

During an outbreak of genital herpes, a number of measures can be taken to make the condition more comfortable: the wearing of loose clothing, avoiding excessive heat or sunlight, keep the sore area clean and dry, place cool or lukewarm cloths on the sore area for short periods of time, do not use perfumed soaps, sprays, feminine deodorants or douches and take aspirin, acetaminophen or ibuprofen for the pain.

Sun protection is also important in preventing recurrences of facial herpes simplex as sun exposure often triggers this type of herpes. Sun protection using high protection factor sunscreens and other measures such as protecting lip balm are important.

Antiviral drugs will stop the herpes simplex virus multiplying once it reaches the skin or mucous membranes but cannot eradicate the virus from its resting stage within the nerve cells. Topical acyclovir or penciclovir, in the form of a cream applied to the affected areas, shortens attacks of recurrent herpes simplex provided the application is started early enough. Undecylenic acid (Castor oil derivative) is proven to have anti-bacterial and anti-viral properties that are effective on viral skin infections such as the herpes simplex virus and lysine supplementation has been proposed as a complementary therapy for the treatment of herpes simplex. Cimetidine, which is a common component of heartburn medication, has been shown to lessen the severity of herpes zoster outbreaks in several different instances and has offered some relief from simplex.

Local injury to the face, lips, eyes or mouth, as well as through trauma, surgery, wind, ultraviolet light, sunburns, a cold or a depressed immune system are all well established triggers and can cause reactivation of herpes symptoms.

Both herpes simplex viruses 1 and 2 produce similar symptoms but they can differ in severity depending on the site of infection. The symptoms of infection in the genital area for example, include itching, painful sores and blisters (called lesions) on the genitals, fever (usually only with the first outbreak of blisters), tiredness, general discomfort, muscle aches, discharge from the vagina, difficulty or pain when you urinate, pain when you have intercourse and tender or enlarged lymph nodes in the groin.

In rare cases, the virus can also cause more serious infections. When the eye is afflicted by herpes simplex, it usually affects only one eye and most often occurs on the cornea (the normally clear dome that covers the front part of the eye). Less commonly, the simplex virus may also infect the inside of the eye (Herpes Uveitis) or the retina (Herpes Retinitis). The herpes simplex virus can also cause blood vessels to grow onto the cornea and occasionally can lead to significant visual impairment.