HIV (human immunodeficiency virus) is a virus that damages the cells in your immune system and weakens your ability to fight everyday infections and disease.

AIDS (acquired immune deficiency syndrome) is the name used to describe a number of potentially life-threatening infections and illnesses that happen when your immune system has been severely damaged by the HIV virus.

While AIDS cannot be transmitted from 1 person to another, the HIV virus can. There's currently no cure for HIV, but there are very effective drug treatments that enable most people with the virus to live a long and healthy life. 

With an early diagnosis and effective treatments, most people with HIV will not develop any AIDS-related illnesses and will live a near-normal lifespan.

Preventing HIV

Anyone who has sex without a condom or shares needles is at risk of HIV infection. There are many effective ways to prevent or reduce the risk of HIV infection, including:

• using a condom for sex
• post-exposure prophylaxis (PEP)
• pre-exposure prophylaxis (PrEP)
• treatment for HIV to reduce the viral load to undetectable
• if you use drugs, never sharing needles or other injecting equipment, including syringes, spoons and swabs

Speak to your local sexual health clinic or a GP for further advice about the best way to reduce your risk. For people with HIV, if you have been taking effective HIV treatment and your viral load has been undetectable for 6 months or more, it means you cannot pass the virus on through sex. This is called undetectable=untransmittable (U=U).