HIV is a virus most commonly caught by having unprotected sex or by sharing infected needles and other injecting equipment to inject drugs.
HIV stands for human immunodeficiency virus. The virus attacks the immune system, and weakens your ability to fight infections and disease.
AIDS is the final stage of HIV infection, when your body can no longer fight life-threatening infections.
There is no cure for HIV, but there are treatments to enable most people with the virus to live a long and healthy life.
How is HIV spread?
HIV is not spread as easily as some other viruses, such as colds or flu.
HIV is found in the body fluids of an infected person, which includes semen and vaginal fluids, blood, inside the anus and breast milk.
HIV cannot be transmitted by saliva alone. But the saliva of a person with HIV can be infectious if it contains blood or other body fluids.
The most common way of getting HIV in the UK is by unprotected sexual contact with a person who has HIV. This can include vaginal, anal and oral sex. According to statistics from the Health Protection Agency, 95% of those diagnosed with HIV in the UK in 2010 acquired HIV as a result of sexual contact.
Other ways of getting HIV include:
- using a contaminated needle, syringe or other injecting equipment to inject drugs
- tranmission from mother to baby, before or during birth, or by breastfeeding
Read more about what causes HIV.
Getting tested
The only way to find out if you have HIV is to have an HIV test.
If you think you might be at risk of HIV, you should have a test immediately. The earlier HIV is detected, the more likely it is that treatment will be successful.
Emergency anti-HIV medication called PEP (post-exposure prophylaxis) may stop you becoming infected, but treatment must be started within three days of coming into contact with the virus.
It can take several weeks after infection before the virus is picked up in testing, so after your initial test you will be advised to have another one a few weeks later.
There are a number of places you can get an HIV test, including your GP surgery and sexual health clinics and clinics run by the Terrence Higgins Trust.
You may get the results in hours, days or weeks, depending on where you were tested. Find your nearest sexual health clinic.
If your test is positive you will be referred to a specialist HIV clinic where you’ll have more blood tests to show what effect HIV is having on your immune system and be able to discuss treatment options.
Find out more about coping with a positive HIV test.
Gay and bisexual men
HIV is disproportionately common among men who have sex with men.
NICE recommends that annual HIV tests be offered to all men who have sex with men, and more frequent testing be offered to those at higher risk due to multiple partners or unsafe sexual practices.
Living with HIV
Although there is no cure for HIV, treatments are much more successful than they used to be, enabling people with HIV to lead as normal a life as possible.
Medication, known as antiretrovirals, works by slowing down the damage the virus does to the immune system. These medicines come in the form of tablets, which need to be taken every day.
You will be encouraged to take regular exercise, eat a healthy diet, stop smoking and have yearly flu jabs and five-yearly pneumococcal vaccinations to minimise the risk of getting serious illnesses.
Someone with HIV is said to have AIDS when investigations show their immune system has stopped working and they develop life-threatening illnesses such as cancer.
Read more about living with HIV.
Preventing HIV
HIV can affect anybody.
The best way to prevent HIV is to practise safer sex and use a condom. If you inject drugs, do not share needles, syringes or other injecting equipment such as spoons and swabs.
How common is HIV?
At the end of 2010, an estimated 91,500 people in the UK were living with HIV. Of these, around one in four (22,000 in total) did not know they were infected.
That total includes an estimated 40,100 gay men, and an estimated 47,000 heterosexual men and women.
The World Health Organization estimates that around 34 million people in the world are living with HIV.
The virus is particularly widespread in sub-Saharan African countries, such as South Africa, Zimbabwe and Mozambique.
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