Genital herpes - including symptoms, treatment and prevention

Genital herpes is an infection of the skin and mucous membranes (the thin moist lining of many parts of the body such as the nose, mouth, throat and genitals) in the genital and surrounding areas (anus, buttocks and inside of the thighs) caused by the herpes simplex type 1 or 2 viruses. Both types can infect the mouth (producing cold sores) or the genital area (genital herpes). In people under 25 years of age, herpes simplex type 1 virus is more common in genital herpes, while in people 25 years of age and older, genital herpes is most often caused by herpes simplex type 2 virus.

How genital herpes is spread

Herpes simplex virus is usually spread by contact with blisters. However, people with genital herpes can shed the virus from the genital area and infect others even without a blister being present. Cold sores on the mouth are a potential source of genital infection during mouth-to-genital contact (oral sex).

Infection of a baby can occur during vaginal delivery if the mother has genital herpes, particularly if it is the first attack. Babies infected in this way can become severely ill. The obstetrician and midwife should be told of past genital herpes infections so the risk of this complication can be minimised.

Signs and symptoms

When a person is infected with the herpes virus, it may pass unnoticed. This is called subclinical infection. Therefore many people with genital herpes are not aware they have the infection.

Symptoms, if they do occur, include small painful blisters that break open to form shallow painful sores or ulcers. The sores scab and heal after 1 to 2 weeks. The first attack may be very severe with multiple blisters.

In the first episode, general flu-like symptoms may occur – feeling unwell, fever, headaches or pains in the back and legs. 

Having a sexually transmitted infection (STI) such as genital herpes, increases the risk of getting HIV infection if you are exposed to HIV.

There is no evidence that women with a history of genital herpes need to have Pap smears more frequently than other women.

Recurrent outbreaks

After the first infection, the virus remains in the body for life and may produce sores at a later date. These are called recurrent outbreaks. These are usually shorter, not as painful as the first attack, and can be triggered by:

  • physical stress
  • emotional stress
  • sunlight
  • a viral infection
  • hormonal changes (including menstruation)

Often no trigger can be identified.

Flu-like symptoms experienced in the first episode do not usually occur with later outbreaks.

In most cases, recurrent outbreaks become less frequent with time and may eventually stop altogether. Recurrent attacks are caused by reactivation of the virus already present in the body – not by being re-infected.


Herpes is diagnosed by taking a sample from an infected area during an outbreak. The herpes virus will usually grow from a swab taken from a ruptured blister. The test will identify the strain (type 1 or type 2) of the herpes virus. PCR (polymerase chain reaction) tests in a pathology laboratory may also be used. Blood tests may assist diagnosis in some cases, but the results can be difficult to interpret.

Incubation period

(time between becoming infected and developing symptoms)

2 to 12 days.

Infectious period

(time during which an infected person can infect others)

Spread of infection is most likely when a moist blister is present. However, people with a history of genital herpes may shed the virus (and are capable of infecting others) even without a blister being present.


Specific antiviral therapy is available which can decrease the severity of initial genital herpes infection, decrease the severity of recurrences and if taken continuously, reduce the likelihood of recurrences.

For severe infections, salt baths or ice packs may reduce discomfort. Iodine-containing antiseptics such as Betadine will dry out the blisters and may help prevent secondary infection.


  • People should not have genital, oral or anal sex while sores or blisters are present. However, it is important to remember that it is possible to transmit infection even if there are no obvious blisters, sores or other symptoms.
  • When blisters are not present, the spread of herpes simplex may be reduced by using condoms or dental dams.
  • Testing to exclude other sexually transmitted infections is advisable.
  • Since herpes in pregnant women may be transmitted to the baby at delivery, the obstetrician and midwife should be alerted to a history of past herpes infections so that this complication can be planned for and avoided.

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