What is HIV?

A photo of Naveen Puri
Medical Director, Bupa UK Insurance
24 May 2022
Next review due May 2025

Human immunodeficiency virus (HIV) is a virus which affects your immune system. This is because it lowers the number of some types of cells in your body that fight disease. You might be very worried if you think there’s a chance you have HIV. But there has been a lot of progress in HIV treatment. Here, I talk about what HIV is, how you get it, symptoms of HIV and how HIV treatment works.

doctor reading on a tablet

How do you get HIV?

The HIV virus enters your body through bodily fluids, such as blood and semen. You can get HIV in a few different ways including:

  • having anal or vaginal sex with someone who has HIV, without using a condom
  • sharing of needles, for example through drug use

HIV can also sometimes be passed on during childbirth or through breastmilk. But, with proper care and the right HIV treatment, the chances of you passing on HIV to your baby are very low.

You can’t get HIV from shaking hands, hugging or kissing people. You also can’t get HIV by sharing common household items such as knives or forks, or from toilet seats.

What are the symptoms of HIV?

Early symptoms of HIV can include fever, sore throat, headaches, weight loss and a rash. These symptoms tend to develop between one and six weeks after infection, and then go away soon afterwards. You also may not have any symptoms at all. The HIV virus can live in your body for a very long time before any symptoms begin to show. If you’ve had HIV for a long time you may get illnesses. This is due to your immune system becoming weaker.

How can I reduce my risk of getting HIV?

There are a few different ways to prevent HIV infection.


Condoms are the most effective way to prevent HIV. If condoms are used properly, they’re almost 100 per cent effective in preventing HIV transmission.


You might have also heard of pre-exposure prophylaxis (PrEP) and post exposure prophylaxis (PEP). PrEP and PEP are medicines to help stop you from getting HIV.

In the UK, if you’re assessed as high risk for HIV, you may be able to get PrEP for free at a sexual health clinic. It can be taken as tablets and your doctor will tell you how and when to take them. If taken correctly, PrEP can be very effective in preventing you from getting HIV.

PEP is a medicine that you can take if you may have been exposed to HIV. You can get it for free on the NHS, but a health professional will need to check whether you meet guidelines for PEP. You can usually get PEP at a sexual health clinic.

If you can’t access a sexual health clinic (for example, if it’s outside of normal opening hours) you’ll need to go to A&E for PEP. It’s important to know that PEP is not 100 per cent effective. It should be taken very soon after you have been exposed to HIV, and always within 24 hours. This will give you the best possible chance of not getting HIV. If it’s been longer than 72 hours after you were exposed to HIV, you are unlikely to be offered PEP.

Testing for HIV

If you think you could have HIV, speak to a doctor about getting tested. This can be done at a clinic where a health professional will test a blood sample or saliva (spit) sample. You can also do a HIV test at home.

If your test result is positive this means that you are likely to have HIV. A doctor will always repeat the test to make sure the positive result was correct. They will then discuss treatments with you.

If you don’t have HIV, your doctor can give you advice on how to best protect yourself from getting HIV in the future.

What treatment is there for HIV?

The main type of HIV treatment is anti-retroviral therapy (ART), also known as highly active anti-retroviral therapy (HAART). ART aims to stop the virus from multiplying inside your body. ART can also stop you from spreading HIV to other people. There are different types of ART which can be given to you as tablets. You might take tablets in different combinations and some people refer to this as combination therapy. Your doctor will be able to tell you what ART drugs would be best for you.

Is HIV curable?

There is no cure for HIV yet. However, if HIV is diagnosed early, and you get the right treatment, your life expectancy can be the same as somebody without HIV. Successful treatment can also mean that you’re not able to pass HIV onto anybody else.

What is AIDS?

If it isn’t treated, HIV can develop into advanced HIV which is also known as late-stage HIV. You may have also heard advanced HIV called acquired immunodeficiency syndrome (AIDS). This is where your immune system is very weak, and rare or unusual infections (sometimes called opportunistic infections) can make you very unwell. When you have HIV and you get one of these infections, it’s called an “AIDS-defining illness”. You are then said to have AIDS.

In the UK, most people on effective treatment for HIV don’t go on to develop AIDS, because modern treatments are so effective. This is why it’s important to speak to a doctor and get tested if you think there is a chance you could have HIV. They can then give you the treatment that you need.

A photo of Naveen Puri
Dr Naveen Puri
Medical Director, Bupa UK Insurance

    • HIV infection and AIDS. NICE Clinical Knowledge Summaries., last revised May 2021
    • Human Immunodeficiency Virus. Patient., last edited September 2020
    • HIV infection – BMJ Best Practice., last updated April 2022
    • Terrance Higgins Trust.
    • BHIVA/BASHH guidelines on the use of HIV pre-exposure prophylaxis (PrEP) 2018. British HIV Association, British Association for Sexual Health., published 2018
    • UK Guideline for the use of HIV Post-Exposure Prophylaxis 2021 (post consultation version) British HIV Association, British Association for Sexual Health., published 2021
    • British HIV Association/British Association for Sexual Health and HIV/British Infection Association Adult HIV Testing Guidelines 2020. British HIV Association, British Association for Sexual Health and HIV, British Infection Association Adult HIV., published 2020

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