Genital Herpes

Genital herpes is a long-term condition caused by the herpes simplex virus (HSV). After you have become infected, the virus remains dormant (inactive) for most of the time. There are often few or no initial symptoms. However, certain triggers can activate the virus, causing outbreaks of painful blisters on your genitals and the surrounding areas. There's no cure for genital herpes, but the symptoms can usually be effectively controlled using antiviral medicines. Genital herpes is caused by the Herpes Simplex Virus (HSV) type 1 or type 2. It causes painful blisters to appear on the genitals and the surrounding areas. As genital herpes can be passed to others through intimate sexual contact, it is often referred to as a sexually transmitted infection (STI).

Genital herpes is a chronic (long-term) condition, with most individuals having recurrences. The average rate of recurrence is four to five times in the first two years after being infected. However, over time, the frequency of attacks decreases and the condition becomes less severe with each subsequent occurrence. HSV can affect any mucous membrane (moist lining), for example those found in the mouth, eyes, anal or vaginal areas. When around the mouth, HSV can cause blister-like lesions called cold sores to develop. Genital herpes is a common condition, especially between people aged 20-24 years.

The Herpes Simplex Virus (HSV)

HSV is highly contagious and can be passed easily from one person to another by direct contact. Genital herpes is usually transmitted by having sex (vaginal, anal or oral) with an infected person. Even if someone with genital herpes does not have any symptoms, it is possible for them to pass the condition on to a sexual partner. Once someone has been exposed to HSV, the virus remains dormant (inactive) most of the time. At least 8 out of 10 people who carry the virus are unaware that they have been infected because there are often few or no initial symptoms. However, certain triggers can activate the virus, causing an outbreak of genital herpes.

Symptoms of Genital Herpes

Most people with the herpes simplex virus (HSV) do not experience any symptoms of genital herpes when they are first infected and, as a result, they do not know they have the condition. Symptoms of genital herpes may not appear until months or sometimes years after you are exposed to HSV (usually by close sexual contact with someone who has the virus). If you experience symptoms when you are first infected, they begin to appear four to seven days after you have been exposed to the virus. A case of genital herpes that occurs when you are first infected is known as a primary infection. The symptoms in cases of primary infections are usually more severe than those in cases of recurrent infections.

Primary Herpes infection

A primary infection of genital herpes can cause several different symptoms including:

  • painful red blisters that burst to leave open sores around your genitals, rectum (back passage), thighs and buttocks
  • blisters and ulcers on the cervix (lower part of the womb)
  • vaginal discharge
  • pain when you pass urine
  • a high temperature (fever) of 38°C (100.4°F) or over
  • a general feeling of being unwell, with aches and pains

These symptoms may last for up to 20 days. However, the sores will eventually scab and heal without leaving any scarring.

Recurrent Herpes infections

Once a primary infection of genital herpes has subsided your symptoms will disappear, but HSV will remain dormant (inactive) in a nearby nerve. The virus may be reactivated from time to time, travelling back down the nerve to your skin and causing recurrent infections. If you have a recurrent infection of genital herpes, the symptoms and signs may include:

  • a tingling, burning or itching sensation around your genitals, and sometimes down your leg, before your blisters appear (this can signal the onset of a recurrent infection)
  • painful red blisters that soon burst to leave sores around your genitals, rectum (back passage), thighs and buttocks
  • blisters and ulcers on the cervix (lower part of the womb)

Recurrent infections of genital herpes are usually shorter and less severe than primary infections. This is because your body has produced protective antibodies (proteins that fight infection) in reaction to the previous infection. Your body now recognises the virus and mounts a response that is able to fight HSV more effectively.

Your symptoms may last for up to 10 days and, in most cases, you will not have any of the other symptoms that are associated with a primary infection, such as a fever or generally feeling unwell. In some cases, the blisters and ulceration may also occur in the same area each time you have a recurrent infection. Over time, you should find that any recurrent genital herpes infections become less frequent and less severe. Genital herpes that is caused by type 1 herpes simplex virus (HSV-1) tends to recur less often than infections that are caused by type 2 herpes simplex virus (HSV-2)..

Transmission of Herpes Virus

Genital herpes is caused by the herpes simplex virus (HSV). There are two types of HSV:

  • Type 1 (HSV-1)
  • Type 2 (HSV-2)

Genital herpes is caused by both type 1 and type 2 HSV.

The virus is very contagious and spreads from one person to another through skin-to-skin contact, such as during vaginal, anal or oral sex. Whenever HSV is present on the surface of your skin it can be passed on to a partner. The virus passes easily through the moist skin that lines your genitals, mouth and anus. In some cases it is also possible to become infected by coming into contact with other parts of the body that can be affected by HSV, such as the eyes and skin. For example, you can catch genital herpes if you have oral sex with someone who has a cold sore. A cold sore is a blister-like lesion around the mouth that is also caused by HSV.

Genital herpes cannot usually be passed on through objects, such as towels, cutlery or cups because the virus dies very quickly when it is away from your skin. However, you may become infected by sharing sex toys with someone who has the virus. Genital herpes is particularly easy to catch when an infected person has blisters or sores. However, it can be caught at any time, even when someone has no symptoms at all. Once you have been infected with HSV, it can be reactivated every so often to cause a new episode of genital herpes. This is known as recurrence.

Triggers of Recurrent Herpes

It is not completely understood why HSV is reactivated, but certain triggers may be responsible for the symptoms of genital herpes recurring. For example, friction in your genital area during sexual intercourse may cause a recurrence. Other possible triggers include:

  • being unwell
  • stress
  • drinking excess amounts of alcohol
  • exposure to ultraviolet light, for example, using sunbeds
  • surgery on your genital area
  • having a weakened immune system (the body’s natural defence system), for example, as a result of having chemotherapy (treatment for cancer)

Diagnosis of Genital Herpes

Genital herpes can be diagnosed more easily and accurately when the infection is still present, so you should seek medical attention as soon as you develop symptoms.

If you think that you may have genital herpes for the first time (a primary infection), you should visit your local sexual health clinic as soon as possible. Wherever possible, an initial diagnosis of genital herpes should be made by a GUM specialist. A swab will be used to collect a sample of fluid from a blister. The sample will be sent to a laboratory to be tested for the herpes simplex virus (HSV). You should be aware that even if your swab result comes back negative for HSV, you may still have genital herpes. See your GP if you have previously been diagnosed with genital herpes and you think that you may have a recurrent infection.

If you have genital herpes and you are pregnant, it is very important that you are referred for specialist treatment. This is because there may be a chance that the infection could pass to your unborn baby. You should also be referred for specialist treatment if you have a weakened immune system (the body’s natural defence system), for example, if you: have HIV and AIDS or if you are receiving chemotherapy (treatment for cancer). People with a weakened immune system will need specialist treatment because genital herpes can last longer and be more severe in these people.

Treating genital herpes

Treatment for genital herpes will depend on whether: you have the infection for the first time (a primary infection) or you have an infection that keeps coming back (a recurrent infection)

Primary infection – Your GUM Specialist or GP may prescribe antiviral tablets, called Aciclovir, which you will need to take five times a day. Aciclovir works by preventing HSV from multiplying. However, it does not clear the virus from your body completely and does not have any effect once you stop taking it. You will need to take a course of aciclovir for at least five days, or longer if you still have new blisters and ulcers (open sores) forming on your genital area when your treatment begins. Aciclovir can cause some side effects, including: feeling sick, being sick & headaches

Recurrent infections - You should visit your GP if you have been diagnosed with genital herpes before and you are experiencing a recurrent infection. In most cases, you will not need to return to your local GUM clinic. If the symptoms of your recurrent infection are mild, your GP may suggest some self-help measures to help ease your symptoms without the need for treatment. If your symptoms are more severe, you may be prescribed antiviral tablets (aciclovir), which you will need to take five times a day for five days. If you have fewer than six recurrent infections of genital herpes in a year, your GP may prescribe a five-day course of aciclovir each time you experience symptoms. This is known as episodic treatment. If you have more than six recurrent attacks of genital herpes in a year, or if your symptoms are particularly severe and causing you distress, you may need to take aciclovir every day as part of a long-term treatment plan. This is known as suppressive treatment and it aims to prevent further recurrent infections from developing. In this instance, it is likely that you will need to take aciclovir twice a day for 6 to 12 months. It is important to note that while suppressive treatment can reduce the risk of passing HSV on to your partner, it cannot prevent it altogether. Your GP may refer you for specialist advice if you are concerned about transmitting the virus to your partner while you are having suppressive treatment. After you have been taking aciclovir for 12 months, your GP will usually stop your suppressive treatment. You may continue to experience further recurrent infections of genital herpes after your treatment has been stopped. If you are experiencing recurrent attacks of genital herpes you should consider being tested for HIV. Recurrent attacks may be a sign of a weakened immune system (the body’s natural defence against infection and illness), which may indicate that you have HIV.


If your symptoms of genital herpes are mild, you may not need to have any treatment from your GP or a genitourinary medicine (GUM) specialist. The advice below may help to ease your symptoms.

  • Painkillers, such as paracetamol, can be taken to ease any pain that you have.
  • Keep the affected area clean using either plain or salt water. This will help to prevent the blisters or ulcers (open sores) from becoming infected and may encourage them to heal quicker. It will also stop the affected areas from sticking together and healing in the wrong position.
  • Apply petroleum jelly, such as Vaseline, or an anaesthetic (painkilling) cream to any blisters or ulcers to reduce the pain when you pass urine.
  • Drink plenty of fluids to dilute your urine. This will make passing urine less painful. Passing urine while sitting in a bath or while pouring water over your genitals may also make urinating less painful.
  • Avoid wearing tight clothing because it may irritate the blisters and ulcers.
  • Avoid sharing towels or flannels with others to ensure that you do not spread the herpes simplex virus (HSV).
  • Avoid having sexual intercourse, including vaginal, anal and oral sex, until your GP or GUM specialist advises that you can, or until all your blisters and ulcers have cleared up.
  • If you have a recurrent infection of genital herpes, you should avoid anything that appears to trigger an infection, such as excess alcohol and stress

Complications of genital herpes

In rare cases, the blisters that are caused by the herpes simplex virus (HSV) can become infected by other bacteria. If this happens, it could cause a skin infection to spread to other parts of your body.

Genital Herpes and Pregnancy

In some instances, the herpes virus can pose problems during pregnancy and may be passed to the baby around the time of the birth.

Existing genital herpes

If you had genital herpes before becoming pregnant, the risk to your baby is very low. This is because during the last few months of your pregnancy, you will pass all the protective antibodies (proteins that fight infection) to your baby. These will protect your baby during the birth and for several months afterwards.

Even if you have recurrent episodes of genital herpes throughout your pregnancy, your baby should not be at increased risk. However, you may need to take the antiviral medication, aciclovir, continuously from week 36 of the pregnancy until the birth to reduce the severity of your symptoms. If you have genital herpes blisters or ulcers (open sores) at the time of the birth, the chance of passing the infection on to your baby is up to 3 in 100.

First and second trimester

If you develop genital herpes for the first time (primary infection) during the first or second trimester, which is up to week 26 of the pregnancy, you may be at risk of having a miscarriage (losing the pregnancy). There is also an increased risk of passing the virus on to your baby. To prevent this, you may need to take antiviral medicine, such as aciclovir, while you are pregnant.

Third trimester

If you develop genital herpes for the first time during the third trimester (week 27 of the pregnancy until birth), particularly during the last six weeks of the pregnancy, the risk of passing the virus on to your baby is considerably higher. This is because you will not have time to develop any protective antibodies to pass to your baby, and the virus can be passed to your baby before or during the birth.

To prevent this happening, you may need to have a caesarean section delivery. If you give birth vaginally, the risk of passing the virus on to your baby is around 4 in 10. If you develop genital herpes during the latter stages of pregnancy, you will need to take antiviral medicine continuously for the last four weeks of your pregnancy. However, this may not prevent the need for a caesarean.

Neonatal herpes

Neonatal herpes is where a baby catches the herpes simplex virus around the time of the birth. It can be serious and, in some cases, it can be fatal. However, in the UK neonatal herpes is rare, affecting one or two babies in every 100,000 live births. There are three types of neonatal herpes that affect different parts of the body. Neonatal herpes can affect: 1) the eyes, mouth and skin, 2) the central nervous system (brain, nerves and spinal cord), 3) multiple organs. In babies with symptoms affecting only their eyes, mouth or skin, most will make a complete recovery with antiviral treatment. However, the condition is much more serious in cases where multiple organs are affected and nearly a third of infants with this type of neonatal herpes will die.


The following advice can help to prevent the herpes simplex virus (HSV) spreading to others.

  • Avoid having sex - If you have genital herpes, you should avoid having sex (vaginal, anal and oral) until any blisters or ulcers (open sores) around your genital area have cleared up. It is best not to have sex if you have symptoms of genital herpes because at this point the condition is very contagious, even from the first tingle or itch.
  • Always use a condom - Always use a condom while you are having any kind of sexual intercourse (vaginal, anal and oral), even after your symptoms have gone. This is particularly important when having sex with new partners. However, while using a condom may help to prevent genital herpes from spreading, the condom only covers the penis. If the virus is also present on or around your anus (the opening where solid waste leaves the body), it can still be passed on through sexual contact. As HSV survives within the nerves of your skin, the virus may still be present on your skin after you no longer have any symptoms. This means that there is still a chance you could pass it on to someone else.
  • Testing your partner - If you have genital herpes, you should encourage your partner to visit a sexual health clinic. They should be tested for the condition, even if they do not have any symptoms of genital herpes. A first case of genital herpes (a primary infection) often develops some time after exposure to the virus, so they may be unaware that they are infected.
  • Avoid sharing towels or flannels - Although it is very unlikely that HSV would survive on an object long enough to be passed on to someone else, it is a good idea to take precautions to prevent this from happening. Therefore, you should avoid sharing towels or flannels to ensure that you do not spread HSV to others