What is HIV?

HIV stands for human immunodeficiency virus.

This particular virus was identified in the 1980s and belongs to a group of viruses called ‘retroviruses’.

HIV attacks the immune system, and gradually causes damage. This can mean that, 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.

Current treatment for HIV works by reducing the amount of HIV in the body so the immune system can work normally. This doesn’t get rid of HIV completely, but with the right treatment and care, someone with HIV can expect to live a long and healthy life.

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.

A test can tell if you have HIV. If you do, this is described as being HIV positive.

Where next?

What is the link between HIV and AIDS?

AIDS stands for acquired immune deficiency syndrome.

AIDS is the name used to describe a combination of potentially life-threatening infections and cancers, which can develop when someone’s immune system has been damaged by HIV.

You cannot catch AIDS and there is no AIDS test. HIV causes AIDS and it is HIV that can be passed on.

Being diagnosed with AIDS means different things for different people. Just because someone has AIDS does not mean they will die – but it is important to have medical care and treatment.

Treatment with combinations of anti-HIV drugs can keep the immune system strong, and because of this the number of people who are diagnosed with AIDS has fallen. Thanks to effective HIV treatment, many people who developed AIDS are now very well and can look forward to a long and healthy life.

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What are the symptoms of HIV?

Symptoms vary from person to person. The only way to be sure if you have HIV is to have an HIV test. You cannot tell from symptoms alone.

If you have HIV, it’s very important that it’s diagnosed, for the best chance of getting treatment and care, and of staying well.

Many people have a short, flu-like 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 that it passes without being noticed. 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 at the time.

If you think you might have been at risk of HIV (for example you’ve had unprotected sex) and notice these symptoms about two weeks later, you might want to consider having an HIV test.

After this initial illness, it’s not uncommon for people to live with HIV and not to have any symptoms at all. But the virus will still be causing damage to the immune system, and without treatment most people with HIV will eventually become ill because of it.

HIV-related illnesses can cause a wide range of symptoms. These can include fevers and night sweats, a high temperature, a cough that won’t go away, unexplained weight loss, severe diarrhoea, bad headaches, or persistent mouth and skin problems. Of course, these can all have other causes.

How do I know if I have HIV?

Having an HIV test is the only way to know for sure whether you have HIV.

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.

Usually, when you go for an HIV test, you will have an opportunity to talk to someone first, so you can ask any questions you might have. The person doing the test will explain how the test works and how you will get the results.

Then, depending on the type of test, you have a small sample of blood taken from your arm, or a drop of blood taken from your finger. Some tests are performed using fluid from around your gums.

If the test says you are HIV positive, this means you have HIV. If the test says you are HIV negative, this means you do not have HIV. With some tests, you will need to have a follow-up test if you have a positive result.

In many countries, including the UK, HIV testing is free and confidential.

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How many people have HIV?

The United Nations Programme on HIV/AIDS (UNAIDS) regulary reports on global HIV figures ahead of World AIDS Day on 1 December. It said that in 2016, there were an estimated 36.7 million people living with HIV worldwide. There were an estimated 1.8 million new HIV infections in 2016.

It’s difficult to say for sure how many people have HIV, as often people do not realise they have HIV and they may live with HIV for some time before they are diagnosed.

UNAIDS and the World Health Organization (WHO) produce figures for the global epidemic and also for individual countries, based on numbers collected by the health services in each country.

Public Health England estimated that in 2015 the total number of people living with HIV in the UK was 101,200.

You can find out more about HIV in each country of the world by visiting our e-atlas.

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What is the life expectancy of someone with HIV?

With modern HIV treatment, many people with HIV are living long and healthy lives. In fact, doctors are hopeful that many people with HIV will live as long as their HIV-negative peers.

A lot of effort is going into making effective HIV treatment available to everyone who needs it. However, this is not always possible in some parts of the world. Without treatment, people with HIV will almost always eventually become ill, and their lives may be shortened.

Your best chance of staying well is to start treatment before HIV has done too much damage to your immune system. To do this you need to know you have HIV. Many of the people who die from HIV-related illnesses in countries where treatment is easily available were diagnosed very late, often not until they were already very ill.

How can I support someone I know who has HIV?

This will depend both on your own and the other person’s circumstances, needs and character.

But making it clear that you’re there to offer support, not judging, and listening, are often good places to start.

Learning about HIV, its effects and treatment may help you to understand the experiences of someone with HIV, and to be able to discuss their experience or options.

Finding out about other sources of support – both for the person with HIV and yourself – is also likely to be a good idea. There are many organisations that provide information, advice and support around the world.

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Where did HIV come from?

HIV is very similar to a virus called SIV (simian immunodeficiency virus), which is found in monkeys.

There’s now good evidence that it jumped species to humans, probably in the late 19th or early 20th century. The most common theory suggests that this happened during hunting and butchering of primates such as chimpanzees.

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How has HIV affected the world?

Untreated HIV eventually leads to AIDS. The first cluster of AIDS cases were reported in the US in 1981. Doctors noticed that gay men were becoming ill with a rare form of pneumonia (PCP) and a cancer called Kaposi’s sarcoma.

Further cases of AIDS were soon reported in gay men in other countries, including the UK. But it quickly became apparent that AIDS was affecting other groups as well.

Researchers worked out that these men had an underlying infection, and that it was likely to be sexually transmitted and blood borne.

In the mid-1980s, the virus that is now known as HIV was identified.

Even before HIV was discovered, safer sex and safer drug use had become established ways of reducing the risk of the illness.

As the virus spread around the world and deaths mounted, research went into finding a cure or vaccine. Drugs were developed, but it became clear that treatment with one drug alone did not work well in the long term. Treatment with two anti-HIV drugs was shown to have more benefit, but the real breakthrough came with development of new anti-HIV drugs that worked against the virus in a number of different ways.

In 1996, triple-drug HIV treatment (often called ‘combination’ therapy or highly active antiretroviral therapy, or HAART) was introduced. This treatment was able to reduce the amount of virus in the blood and allow the immune system to strengthen. Thanks to this treatment, the number of AIDS deaths fell dramatically in countries where treatment was widely available.

However, HIV was spreading rapidly in some of the world’s poorest countries, especially in southern Africa, and wider access to HIV treatment in these countries is only now starting to become a reality.

The early HIV treatment combinations were difficult to take and many caused unpleasant and long-term side-effects.

More powerful, easier-to-take and safer drugs gradually became available. Thanks to these, and other improvements in HIV care, doctors are increasingly hopeful that many people with HIV will be able to live a normal lifespan.

Nevertheless, HIV continues to spread and HIV is now firmly established as an important health issue in the 21st century, and one of the most significant causes of illness and death in human history.

Where next?

What are co-infections?

Tuberculosis (TB) and hepatitis are common in people who also have HIV. These are diseases that can have an effect on HIV and can also be affected by HIV. They are sometimes referred to as co-infections.

Hepatitis B and C are more infectious than HIV, but are transmitted in similar ways: by contact with infected body fluids like blood, semen and vaginal fluid, and from a mother to her baby during pregnancy or delivery.

Both these types of hepatitis can cause serious liver damage, and liver disease is a major cause of serious illness and death in people with hepatitis co-infection.

There is a vaccine against hepatitis B. It works well in people with HIV, and it is recommended that people who have HIV receive it.

There is no vaccine against hepatitis C. Hepatitis C can be cured and new treatments are becoming available which have fewer side-effects and don't need to be taken for as long a period as older drugs. However, these new treatments are expensive. Due to their high prices, the new drugs are not available to everyone with hepatitis C in the UK and in many other countries

Tuberculosis, or TB, is one of the most common AIDS-defining illnesses.

The bacteria that cause TB can pass from one person to another through the air. When someone who is ill with TB in the lungs or throat coughs or sneezes, TB bacteria are released into the air.

TB doesn’t always cause someone to be ill, but if the immune system is weakened it is more likely. The symptoms of active TB include a cough lasting more than three weeks, fever, loss of appetite, night sweats, tiredness and weight loss. It mostly affects the lungs but can affect other parts of the body.

TB is treated with a combination of antibiotics, normally taken for six months. In some cases, it may be necessary for treatment to last longer.

The basics

Looking for the basics series of illustrated leaflets? You can read or download them from the 'Resources' section of the website.

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Community Consensus Statement on Access to HIV Treatment and its Use for Prevention

Together, we can make it happen

We can end HIV soon if people have equal access to HIV drugs as treatment and as PrEP, and have free choice over whether to take them.

Launched today, the Community Consensus Statement is a basic set of principles aimed at making sure that happens.

The Community Consensus Statement is a joint initiative of AVAC, EATG, MSMGF, GNP+, HIV i-Base, the International HIV/AIDS Alliance, ITPC and NAM/aidsmap

This content was checked for accuracy at the time it was written. It may have been superseded by more recent developments. NAM recommends checking whether this is the most current information when making decisions that may affect your health.

NAM’s information is intended to support, rather than replace, consultation with a healthcare professional. Talk to your doctor or another member of your healthcare team for advice tailored to your situation.