HIV – How is it transmitted?

How is HIV passed on?

HIV can be passed on if the body fluids of a person who has HIV enter the bloodstream of someone who does not have HIV.

Body fluids that contain enough HIV to infect someone are:

  • Sperm and seminal fluids
  • Vaginal fluids, including menstrual fluids
  • Breast milk
  • Blood

Other body fluids like saliva, sweat or urine do not have enough of the virus in them to infect other people.

You cannot get HIV through social contact such as kissing, hugging, shaking hands, sharing the same toilet, sharing crockery or cutlery.


Here are some of the ways in which HIV can be passed on:

Sexual transmission

HIV is most commonly transmitted via unprotected sex. Unprotected anal or vaginal sex without a condom increases the risk of passing on the infection if one of the partners has HIV. HIV infection via oral sex is rare.

The risk of acquiring HIV is increased if either partner has an existing Sexually Transmitted Infection.

Consistent and proper use of condoms and dams offer the best form of protection against HIV.


Sharing injecting / snorting equipment for drug use

(including image and performance enhancing drugs e.g. steroids or tanning agents and new psychoactive substances)


Sharing injecting or snorting equipment is a high risk activity for transmission of blood borne viruses including HIV, hepatitis C and hepatitis B. People who inject drugs (and those who use image and performance enhancing drugs) are encouraged to use sterile equipment for each injecting episode and not to share equipment with others. Injecting and snorting equipment includes needles, syringes, water, filters, spoons, swabs, acidifiers, tourniquets and straws.  Injecting equipment provision services are available in each local authority area.


Mother to Baby transmission

It is possible for HIV to be passed from mother to baby. All pregnant women are offered an HIV test.

If a pregnant mother receives an HIV diagnosis, this does not mean that her baby will automatically have HIV. With the right support, guidance and treatments, the risk of mother to baby transmission can be reduced to less than 1%.


Blood to blood

Bleeding on its own is not enough to pass on HIV. The blood of someone needs to leave the body and enter the bloodstream of an uninfected person. In the UK, all blood products and donations are screened for HIV. There may be risk if you receive medical treatment in countries that may not have strict controls or where infection control procedures may be poor.


Tattoos or piercings

Any procedure where there is a risk of blood to blood contact may pose a risk of infection. Getting a tattoo, piercing or acupuncture from unsterile equipment may pose a risk. Registered or licensed premises should be used where sterile equipment and fresh inks are used between each person.


If you think you may have been at risk of HIV – get tested.

You cannot catch HIV from hugging, kissing, shaking hands, sharing the same toilet, sharing crockery or cutlery.