There are many effective ways to prevent or reduce the risk of HIV infection. Speak to your local sexual health clinic or a GP for further advice about the best way to reduce your risk.
When someone with HIV takes effective treatment it reduces their viral load to undetectable levels. This means the level of HIV virus in the blood is so low that it cannot be detected by a test.
Having an undetectable viral load for 6 months or more means it is not possible to pass the virus on during sex. This is called undetectable=untransmittable (U=U), which can also be referred to as "treatment as prevention".
A condom is the most effective form of protection against HIV and other STIs. It can be used for vaginal and anal sex, and for oral sex performed on men.
HIV can be passed on before ejaculation through pre-cum and vaginal secretions, and from the anus.
It's very important condoms are put on before any sexual contact occurs between the penis, vagina, mouth or anus.
Lubricant, or lube, is often used to enhance sexual pleasure and safety by adding moisture to either the vagina or anus during sex.
Lubricant can make sex safer by reducing the risk of vaginal or anal tears caused by dryness or friction, and can also prevent a condom tearing.
Only water-based lubricant (such as K-Y Jelly) rather than an oil-based lubricant (such as Vaseline or massage and baby oil) should be used with condoms.
Oil-based lubricants weaken the latex in condoms and can cause them to break or tear.
If you inject drugs, this could expose you to HIV and other viruses found in blood, such as hepatitis C.
It's important not to share needles, syringes, injecting equipment such as spoons and swabs, or the actual drugs or liquids used to dilute them.
Many local authorities and pharmacies offer needle exchange programmes, where used needles can be exchanged for clean ones.
If you're a heroin user, consider enrolling in a methadone programme. Methadone can be taken as a liquid, so it reduces your risk of getting HIV.
A GP or drug counsellor should be able to advise you about both needle exchange programmes and methadone programmes.
If you're having a tattoo or piercing, it's important that a clean, sterilised needle is always used.
If you're HIV negative, you may be able to take pre-exposure prophylaxis (PrEP) medicine to reduce your risk of getting the virus.
PrEP is available for some people who are at high risk of HIV infection – for example, those whose partner is HIV positive.
It's available as a tablet, and is to be taken before you have sex and are exposed to HIV. You'll be able to get the medicine from sexual health clinics across England.
If pregnant, you'll be offered a blood test to check if you have HIV as part of routine antenatal screening.
If untreated, HIV can be passed to your baby during pregnancy, birth or breastfeeding.