Blisters are the main symptom of herpes. After getting infected you may never get blisters, get them once, or they may come back now and again. Usually they are less painful and frequent over time.

You may see signs of infection within around four to seven days after exposure, but sometimes it can be months or even years after getting infected before symptoms first appear.

A herpes blister can appear on various parts of the body:

• in or around the mouth (known as cold sores) 
• throat 
• penis  
• rectum 
• sometimes on the thighs, buttocks and other areas.

If your eyes are infected the symptoms can include

• eye pain
• a red eye
• watering of your eye
• sensitivity to light
• blurred vision or other changes to your eyesight
• a swollen eyelid
• blisters or a rash on your eyelid or the skin around your eye

You may feel tired, with flu-like aches and swollen glands. Blisters are usually worse the first time they appear.

Before blisters appear, your skin may itch, tingle or feel numb. They can be painful, especially when going to the toilet, and might cause discharge from the penis, or rectum.

Blisters hold an infectious clear liquid before they burst, scab over and heal within two to four weeks.

Herpes is passed on through:

• skin-to-skin contact during vaginal, anal or oral sex without condoms
• sharing sex toys.

Infection is more likely when blisters are on the skin but it sometimes happens when no blisters are present – especially before or straight after an outbreak.

You won’t see any blisters inside the throat or rectum. If you kiss or have oral sex when you have ‘cold sores’ on your mouth (or if you are just about to get one), you risk giving your partner herpes on their lips or genitals.

Condoms (external and internal) cut the risk of getting or passing on herpes if they cover the affected area.

Other types of contraception, such as the contraceptive pill, offer no protection against sexually transmitted infections (STIs).

Wash your hands after touching blisters, especially before handling contact lenses because herpes can cause an eye infection. 

Avoid things that trigger herpes outbreaks such as a lack of sleep, sunbathing or stress.

Having herpes could make it easier for someone to get or pass on HIV. But if HIV drugs have made your viral load undetectable then you cannot pass on HIV.

The herpes virus stays in your body for life but antiviral tablets can help prevent outbreaks, manage symptoms during an outbreak and make blisters heal more quickly.

Suppressive treatment may be used long-term by people who have more than six outbreaks in a year to prevent symptoms, whereas others use episodic treatment when they have an outbreak.

If you live with HIV

If diagnosed early, herpes, although it is not curable, can be easily treated. HIV infection doesn’t affect the treatment regimen.

If you are immunosuppressed, episodes of genital, perianal, or oral herpes may be longer and more severe. Therefore, treatment courses might need to be extended.

When you have herpes, it may put your HIV-negative partners at a higher probability of getting HIV from you. This is because herpes often manifests with ulcers, sores, inflammation or broken skin, and together with HIV viral loads peaks during herpes outbreaks, they may allow HIV to leave your body and expose your partner more easily.

If your viral load stays undetectable and CD4 count remains average, you don’t have to worry – there is no risk of sexually transmitting HIV to HIV-negative partners, even if you have STI.

Certain medications for HIV can have unwanted interactions with oral drugs used for herpes treatment. So, your doctor should be aware of your HIV status and choose the proper treatment. You can verify HIV and non-HIV drug interactions at www.hiv-druginteractions.org/checker.

If you don’t live with HIV

If you have herpes, you are more likely to get HIV than someone STI-free. This is because the same types of behaviour and conditions that may put you at risk of getting a sexually transmitted infection STI increase the risk of getting HIV. The presence of STI manifestations such as ulcers, sores, inflammation or broken skin caused by STI may allow HIV to enter your body more easily.