The causes of reactivation are uncertain, but several potential triggers have been documented. A 2009 study showed the protein VP16 plays a key role in reactivation of the dormant virus.[71] Changes in the immune system during menstruation may play a role in HSV-1 reactivation.[72][73] Concurrent infections, such as viral upper respiratory tract infection or other febrile diseases, can cause outbreaks. Reactivation due to other infections is the likely source of the historic terms 'cold sore' and 'fever blister'.

The HSV viruses multiply in the human cell by overtaking and utilizing most of the human cells functions. One of the HSV steps in multiplication is to take control of the human cell's nucleus and alter its structure. The altered nucleus (enlarged and lobulated or multinucleated) is what actually is used to help diagnose herpes simplex infections by microscopic examination. The reason sores appear is because as they mature the many HSV particles rupture the human cell's membrane as they break out of the cell.

Oral herpes is a viral infection mainly of the mouth area and lips caused by a specific type of the herpes simplex virus. Oral herpes is also termed HSV-1, type 1 herpes simplex virus, or herpes labialis. The virus causes painful sores on the upper and lower lips, gums, tongue, roof of the mouth, inside the cheeks or nose, and sometimes on the face, chin, and neck. Infrequently, it may cause genital lesions. It also can cause symptoms such as swollen lymph nodes, fever, and muscle aches. People commonly refer to the infection as "cold sores."
It can be pretty similar to having flu, Michael says. "When you are infected with herpes you can experience symptoms like fever, muscle aches, swollen lymph nodes, and a general feeling of being unwell." However, many people will not have any symptoms at all - which means until someone notices blisters or sores, they might not realise they have a herpes infection.
Most people with genital herpes have no symptoms, have very mild symptoms that go unnoticed, or have symptoms but do not recognize them as a sign of infection. Genital herpes symptoms include blisters, sharp pain or burning feelings if urine flows over sores, an inability to urinate if severe swelling of sores blocks the urethra (tube from the bladder to outside the vagina), itching, open sores, and pain in the infected area.
HSV-1 and HSV-2 are transmitted by direct physical contact with a sore on an infected person. Facial or lip herpes is most often contracted by kissing someone with a cold sore. Genital herpes is most often contracted during sexual intercourse with a person who has an active genital sore. Genital herpes can also be contracted during or genital sex if a partner has labial herpes.
People who have had HSV-1 are less likely to contract HSV-2 than those who have not. Previous exposure to HSV-1 also decreases the severity of an HSV-2 outbreak. Reoccurrence of the virus is common, and the virus can be active yet asymptomatic. These infections are more likely to be contracted since the person isn’t aware the virus is active. Studies have shown that 50 percent of the cases of sexual transmission of the virus occurred during asymptomatic infections.
Some people experience very mild genital herpes symptoms or no symptoms at all. Frequently, people infected with the virus don't even know they have it. However, when it causes symptoms, it can be described as extremely painful. This is especially true for the first outbreak, which is often the worst. Outbreaks are described as aches or pains in or around the genital area or burning, pain, or difficulty urinating. Some people experience discharge from the vagina or penis.
This means they cannot function independently outside the living cell. Once inside, however, they provide a far different picture. They are parasitic. This means they live off the host at the host’s expense. Unless you have already been exposed to a particular virus, your body is essentially unable temporarily to prevent viral multiplication inside your body.

Condoms offer moderate protection against HSV-2 in both men and women, with consistent condom users having a 30%-lower risk of HSV-2 acquisition compared with those who never use condoms.[49] A female condom can provide greater protection than the male condom, as it covers the labia.[50] The virus cannot pass through a synthetic condom, but a male condom's effectiveness is limited[51] because herpes ulcers may appear on areas not covered by it. Neither type of condom prevents contact with the scrotum, anus, buttocks, or upper thighs, areas that may come in contact with ulcers or genital secretions during sexual activity. Protection against herpes simplex depends on the site of the ulcer; therefore, if ulcers appear on areas not covered by condoms, abstaining from sexual activity until the ulcers are fully healed is one way to limit risk of transmission.[52] The risk is not eliminated, however, as viral shedding capable of transmitting infection may still occur while the infected partner is asymptomatic.[53] The use of condoms or dental dams also limits the transmission of herpes from the genitals of one partner to the mouth of the other (or vice versa) during oral sex. When one partner has a herpes simplex infection and the other does not, the use of antiviral medication, such as valaciclovir, in conjunction with a condom, further decreases the chances of transmission to the uninfected partner.[14] Topical microbicides that contain chemicals that directly inactivate the virus and block viral entry are being investigated.[14]


Herpes is contracted through direct contact with an active lesion or body fluid of an infected person.[31] Herpes transmission occurs between discordant partners; a person with a history of infection (HSV seropositive) can pass the virus to an HSV seronegative person. Herpes simplex virus 2 is typically contracted through direct skin-to-skin contact with an infected individual, but can also be contracted by exposure to infected saliva, semen, vaginal fluid, or the fluid from herpetic blisters.[32] To infect a new individual, HSV travels through tiny breaks in the skin or mucous membranes in the mouth or genital areas. Even microscopic abrasions on mucous membranes are sufficient to allow viral entry.
'Using condoms or dams can help to protect against STIs, but herpes can also be passed on by skin-to-skin contact with the affected area, so it’s strongly recommended that you don’t have sex during this time,' she adds. 'This includes direct genital contact or skin-to-skin contact with the affected area, and doesn’t have to be penetrative sex,' says O’Sullivan.
×