Around 4 out of 5 people with genital herpes have very mild symptoms and may not know they have the condition. Even if symptoms are mild, the virus can still be passed on during sex.

Genital herpes can be caused by the type 1 or type 2 herpes simplex virus (HSV). Around 7 out of 10 people carry the type 1 virus that is responsible for most cases of cold sores on the lips and of genital herpes. Around 1 in 10 people carry the type 2 virus.

Genital herpes is more common in women than in men. Experts believe this may be due to it being easier for a man to pass on genital herpes to a woman than the other way around.

Genital herpes is caused by a virus, the herpes simplex virus or HSV, so antibiotics will not help clear-up the infection. There is no cure for herpes, but antiviral treatments such as aciclovir are available to reduce and prevent outbreaks and decrease the risk of transmission to a partner.

As with other sexually transmitted infections, genital herpes can be spread by close contact or having sex. It can be spread by sharing sex toys but is highly unlikely to be spread by any other means.

Genital herpes can be transmitted even if the infected partner has no symptoms or visible signs or doesn't know he or she is infected.

Washing the genital area doesn't help prevent any sexually transmitted infection (STI), including genital herpes. The best way to prevent any STI is not to have sex, or only to have sex with someone you know is not infected. Condoms give some protection against the herpes simplex virus, but not if the infection is on skin not covered by the condom.

It is possible for a mum with genital herpes to pass on the infection to the baby during birth, but the risk is very small. Neonatal herpes only affects around 1 to 2 out of every 100,000 newborn babies in the UK. Normal vaginal delivery is usually planned unless doctors and midwives have any special concerns. The baby gets protective antibodies from its mother in the womb which help to protect against herpes infection. The risk is higher if the infection took place later in the pregnancy, especially within 6 weeks of giving birth.

The main test for genital herpes is a swab sample taken from a sore for laboratory testing. Genital herpes blood tests can show whether you have herpes and whether it's type 1 or type 2. However, they can't show where in the body the herpes is likely to break out.

When a person is first infected with the herpes simplex virus, which doctors call the primary infection, symptoms can include fever and flu-like symptoms, genital itching, burning and discomfort, vaginal discharge, swollen lymph nodes, and a feeling of abdominal pressure. Symptoms may not appear for some months or even years after being exposed to the herpes simplex virus.

The classic symptom of genital herpes is small fluid-filled blisters that break, forming painful sores that crust and heal. These blisters may last for up to 20 days before scabs form and healing takes place without leaving scars.

After the first episode of a genital herpes infection, some people may never get an episode again. Other people may get more frequent recurrences which may require antiviral medication to help prevent further outbreaks.

Sweating is not known as a commonly reported trigger for genital herpes. However, stress, illness, sunlight, vigorous sex, diet and wearing tight clothes are linked with triggering herpes outbreaks.

Once inside the body, the genital herpes virus travels to the nerve roots near the spinal cord and settles there permanently.

Some people who have recurrent outbreaks of genital herpes feel an outbreak coming a few hours to a couple of days before it happens. They may feel tingling, burning, itching, numbness, tenderness, or pain where the blisters are going to appear. This is called the prodrome.