HIV stands for human immunodeficiency virus. It is a type of virus called a retrovirus. It can be passed from person to person.

HIV attacks the immune system, the system that protects your body from disease. Over time, HIV gradually causes damage to the immune system. As a result, without treatment and care, a person with HIV is at risk of developing serious infections and cancers that a healthy immune system would fight off.

What is AIDS?

AIDS stands for acquired immune deficiency syndrome. It is sometimes referred to as ‘late-stage’ HIV.

Unlike HIV, the virus that leads to AIDS, you can't pass AIDS on or get it from another person. AIDS is not a single illness. It is a term used to describe a collection of infections and cancers that can develop when someone's immune system has been damaged by HIV.

If you develop an illness that is considered 'AIDS defining', you will be diagnosed with AIDS. Some of these illnesses can be serious or even life-threatening, but they can also be treated. An AIDS diagnosis does not mean you will always be ill, or will die – but it is important to have medical care and treatment.

There is no single test for AIDS. You may need to have tests if you have symptoms of a condition that is AIDS-defining.

Without treatment, HIV leads to AIDS. Treatment with combinations of anti-HIV drugs can keep the immune system strong. Many people whose HIV was diagnosed in good time and who are on effective HIV treatment will never go on to develop AIDS.

How is HIV diagnosed?

Symptoms of HIV infection vary from person to person. Having an HIV test is the only way to know for sure whether you have HIV.

If you think you might have been at risk of HIV (for example, if you’ve had unprotected sex), it is a good idea to have an HIV test. If you have HIV, it’s very important that it’s diagnosed. This will give you the best chance of getting the treatment and care you need to stay well.

How will HIV affect my health and life expectancy?

Many people have a short illness, often called a ‘seroconversion’ illness, soon after they are infected with HIV. Typical symptoms include a fever, sore throat, swollen glands, aches and pains, and a blotchy rash.

In some people this illness is so mild, it passes without them noticing it. Some people mistake it for the flu, but for some people it is more severe and they may need to see a doctor. However, because the symptoms are similar to symptoms of many other conditions, HIV might not be diagnosed as a result.

With the right treatment and care, many HIV-positive people can now expect to live just as long as their HIV-negative peers.

How is HIV passed on?

HIV is present in blood, genital fluids (semen, vaginal fluids and moisture in the rectum) and breast milk.

The main ways HIV can be passed on to someone else are:

  • During unprotected anal, vaginal and oral sex by sharing injecting equipment, and from a mother to her baby during pregnancy, birth or through breastfeeding.
  • But there are ways of preventing HIV infection in all of these situations.
  • There is no risk of HIV transmission through social contact such as sharing food, using the same toilet, towels, cutlery or crockery, hugging, kissing or shaking hands.