HIV (human immunodeficiency virus) is a virus that damages 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.



Most people infected with HIV experience a short, flu-like illness that occurs 2-6 weeks after infection.  After this, HIV may not cause any symptoms for several years.
It's estimated up to 80% of people who are infected with HIV experience this flu-like illnes.
The most common symptoms are:
  • raised temperature (fever)
  • sore throat
  • body rash
Other symptoms can include:
  • tiredness
  • joint pain
  • muscle pain
  • swollen glands

The symptoms usually last 1-2 weeks but can be longer.  They're a sign that your immune system is putting up a fight against the virus.

However, having these symptoms doesn't necessarily mean you have the HIV virus.  Remember: they're commonly caused by conditions other than HIV.

If you have several of these symptoms and think you've been at risk of HIV infection within the past few weeks, you should get an HIV test.

After the initial symptoms disappear, HIV may not cause any further symptoms for many years.

During this time the virus continues to be active and causes progressive damage to your immune system.

This process can vary from person to person, but may take up to 10 years, during which you'll feel and appear well.

Once the immune system becomes severely damaged, symptoms can include:

  • weight loss
  • chronic diarrhoea
  • night sweats
  • skin problems
  • recurrent infections
  • serious life-threatening illnesses

Earlier diagnosis and treatment of HIV can prevent these problems.

You should still take an HIV test if you may have been at risk at any time in the past, even if you don't experience any symptoms.

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Who can get it

In the UK, most cases of HIV are caused by having sex with a person who has HIV, and is not on effective treatment, without using a condom.

A person with HIV can pass the virus on to others even if they don't have any symptoms.  People with HIV can pass the virus on more easily in the weeks following their own infection. 

HIV treatment significantly reduces the risk of someone with HIV passing it on

Sexual contact

Most people diagnosed with HIV in the UK acquire the virus through unprotected vaginal or anal sex.

It may also be possible to catch HIV through unprotected oral sex, but the risk is much lower.

The risk is higher if:

  • the person giving oral sex has mouth ulcers, sores or bleeding gums
  • the person receiving oral sex has recently been infected with HIV and has a lot of the virus in their body, or another sexually transmitted infection

Who's most at Risk

People who are at higher risk of becoming infected with HIV include:

  • people with a current or previous partner with HIV
  • people with a current or previous partner who is from an area with high HIV rates
  • people who are from an area with high HIV rates
  • people who engage in chemsex (using drugs to help or enhance sex)
  • men who have unprotected sex with men
  • women who have unprotected sex with men who have sex with men
  • people who inject drugs and share equipment
  • people who have unprotected sex with somebody who has injected drugs and shared equipment
  • people who share sex toys with someone infected with HIV
  • people with a history of sexually transmitted infections, hepatitis B or hepatitis C
  • people who have had multiple sexual partners
  • people who have been raped
  • people who have received a blood transfusion, transplant or other risk-prone procedures in countries that do not have strong screening for HIV
  • healthcare workers who could accidentally prick themselves with an infected needle – but this risk is extremely low
  • babies born from a parent with untreated HIV

How HIV is transmitted

HIV is not passed on easily from one person to another. The virus does not spread through the air like cold and flu viruses.

HIV lives in the blood and in some body fluids. To get HIV, 1 of these fluids from someone with HIV has to get into your blood.

The body fluids that contain enough HIV to infect someone are:

  • semen
  • vaginal fluids, including menstrual blood
  • breast milk
  • blood
  • lining inside the anus

Other body fluids, like saliva, sweat or urine, do not contain enough of the virus to infect another person.

The main ways the virus enters the bloodstream are: 

  • by injecting into the bloodstream with needles or injecting equipment that's been shared with other people
  • through the thin lining on or inside the anus, vagina and genitals
  • through the thin lining of the mouth and eyes
  • through cuts and sores in the skin

HIV is not passed on through: 

  • spitting
  • kissing
  • being bitten
  • contact with unbroken, healthy skin
  • being sneezed on
  • sharing baths, towels or cutlery
  • using the same toilets or swimming pools
  • mouth-to-mouth resuscitation
  • contact with animals or insects like mosquitoes

How HIV infects the body

HIV infects the immune system, causing progressive damage and eventually making it unable to fight off infections.

The virus attaches itself to immune system cells called CD4 lymphocyte cells, which protect the body against various bacteria, viruses and other germs.

Once attached, it enters the CD4 cells and uses it to make thousands of copies of itself. These copies then leave the CD4 cells, killing them in the process.

This process continues until eventually the number of CD4 cells, also called your CD4 count, drops so low that your immune system stops working.

This process may take up to 10 years, during which time you'll feel and appear well. 


The only way to find out if you have HIV is to have an HIV test, as symptoms of HIV may not appear for many years.  Anyone who think they could have HIV should get tested.

HIV testing is provided to anyone free of charge on the NHS. Many clinics can give you the result on the same day. Home testing and home sampling kits are also available.

Request a free home sampling kit.

Some people are at particularly high risk and are advised to have regular tests:

When to get tested

Seek medical advice immediately if you think there's a chance you could have HIV. The earlier it's diagnosed, the earlier you can start treatment and avoid becoming seriously ill.

Some HIV tests may need to be repeated 1-3 months after exposure to HIV infection, but you should not wait this long to seek help.

A GP or a sexual health professional can talk to you about having a test and discuss whether you should take emergency HIV medicine.

Anti-HIV medicine called post-exposure prophylaxis (PEP) may stop you becoming infected if taken within 72 hours of being exposed to the virus. 

Where to get an HIV test

There are various places you can go to for an HIV test, including:

  • sexual health or genitourinary medicine (GUM) clinics
  • clinics run by charities like the Terrence Higgins Trust
  • some GP surgeries
  • some contraception and young people's clinics
  • local drug dependency services
  • an antenatal clinic, if you're pregnant
  • a private clinic, where you will have to pay

There are also home sampling and home testing kits you can use if you do not want to visit any of these places

Types of HIV test

There are 4 main types of HIV test:

  • blood test – where a sample of blood is taken in a clinic and sent for testing in a laboratory. Results are usually available on the same day or within a few days
  • point of care test – where a sample of saliva from your mouth or a small spot of blood from your finger is taken in a clinic. This sample does not need to be sent to a laboratory and the result is available within a few minutes
  • home sampling kit – where you collect a saliva sample or small spot of blood at home and send it off in the post for testing. You'll be contacted by phone or text with your result in a few days. Visit the free HIV testing website to check if you're eligible for a free test. If not, you can buy them online or from some pharmacies
  • home testing kit – where you collect a saliva sample or small spot of blood yourself and test it at home. The result is available within minutes. It's important to check that any test you buy has a CE quality assurance mark and is licensed for sale in the UK, as HIV self-tests available from overseas can be poor quality

If the test finds no sign of infection, your result is "negative". If signs of infection are found, the result is "positive".

The blood test is the most accurate test and can normally give reliable results from 1 month after infection.

The other tests tend to be less accurate and may not give a reliable result for a longer period after exposure to the infection. This is known as the window period.

For all these tests, a blood test should be carried out to confirm the result if the first test is positive.

If this test is also positive, you'll be referred to a specialist HIV clinic for some more tests and a discussion about your treatment options.

Screening for HIV in pregnancy

If you're pregnant, you'll be offered a blood test to check if you have HIV as part of routine antenatal screening.

If untreated, HIV can be passed to your baby during pregnancy, birth or breastfeeding. Treatment in pregnancy greatly reduces the risk of passing HIV on to the baby.


While there's no cure for HIV, there are very effective treatments that enable most people with the virus to live a long and healthy life.

Emergency HIV drugs

If you think you've been exposed to the virus, post-exposure prophylaxis (PEP) medication may stop you becoming infected.

PEP must be started within 72 hours of coming into contact with the virus for it to be effective. It's only recommended following higher risk exposure, particularly where the sexual partner is known to be positive.

PEP involves taking HIV treatment every day for one month. It may cause some side effects.

You should be able to get PEP from:

  • sexual health clinics or genitourinary medicine (GUM) clinics
  • hospitals – usually accident and emergency (A&E) departments

If you already have HIV, try your HIV clinic if the PEP is for someone you've had sex with.

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If you test positive

If you're diagnosed with HIV, you'll have regular blood tests to monitor the progress of the HIV infection before starting treatment.

Two important blood tests are:

  • HIV viral load test – a blood test that monitors the amount of HIV virus in your blood
  • CD4 lymphocyte cell count – which measures how the HIV has affected your immune system

Treatment can be started at any point following your diagnosis, depending on your circumstances and in consultation with your HIV doctor.

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Antiretroviral drugs

HIV is treated with antiretroviral medications, which work by stopping the virus replicating in the body. This allows the immune system to repair itself and prevent further damage.

A combination of HIV drugs is used because HIV can quickly adapt and become resistant.

Some HIV treatments have been combined into a single pill, known as a fixed dose combination, although these often cost more to prescribe.

Usually, people who have just been diagnosed with HIV take between 1 and 4 pills a day.

Different combinations of HIV medicines work for different people, so the medicine you take will be individual to you.

The amount of HIV virus in your blood (viral load) is measured to see how well treatment is working. Once it can no longer be measured it's known as undetectable. Most people taking daily HIV treatment reach an undetectable viral load within 6 months of starting treatment.

Many of the medicines used to treat HIV can interact with other medicines prescribed by your GP or bought over the counter.

These include some nasal sprays and inhalers, herbal remedies like St John's wort, as well as some recreational drugs. Always check with your HIV clinic staff or your GP before taking any other medicines.

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Living with

f you manage your condition properly by taking your medication correctly, you should be able to live a normal life.

As well as taking HIV treatment, there are many things you can do to improve your general health and reduce your risk of falling ill.

These include:

  • exercising regularly
  • eating a healthy, balanced diet
  • stopping smoking

This page covers:

  • other ways HIV may affect your life
  • getting support
  • telling people about your HIV
  • pregnancy
  • the risk of opportunistic infections
  • financial support

Other ways HIV may affect your life

  • you will not be able to donate blood or organs
  • you may have difficulty getting life insurance to cover a mortgage loan – but life insurance is not compulsory when taking out a mortgage unless it's an endowment mortgage, and there are now specialist life insurance policies for people with HIV

There are some countries you will not be able to visit

Psychological impact of HIV

Getting support

As HIV is a long-term condition, you'll be in regular contact with your healthcare team, who will review your treatment on an ongoing basis.

Developing a good relationship with your healthcare team means you can easily discuss your symptoms or concerns. The more the team knows, the more they can help you.

People with HIV are seen at a specialist HIV clinic, which is usually part of a sexual health or infectious diseases clinic at your local hospital.

Find local HIV support services

Psychological support

Being diagnosed with HIV can be extremely distressing, and feelings of anxiety or depression are common.

Your healthcare team can provide you with counselling so you can fully discuss your condition and concerns.

You may find it helpful to talk to a trained counsellor or psychologist, or someone at a specialist helpline. Your HIV clinic will have information about these.

Some people find it helpful to talk to other people who have HIV, either at a local support group or on an internet chatroom.

Want to know more?

Telling people about your HIV

Telling your partner and former partners

If you have HIV, it's important your current sexual partner and any sexual partners you've had since becoming infected are tested and treated.

Some people can feel angry, upset or embarrassed about discussing HIV with their current or former partners. Discuss your concerns with your GP or the clinic staff.

They'll be able to advise you about who should be contacted and the best way to contact them, or they may be able to contact them on your behalf.

They'll also advise you about disclosing your status to future partners and how you can reduce the risk of transmitting the virus to someone else.

Nobody can force you to tell any of your partners you have HIV, but it's strongly recommended that you do.

Left untested and untreated, HIV can have devastating consequences, and eventually lead to serious illness and death.

Telling your employer

People with HIV are protected under the Equality Act (2010)

There's no legal obligation to tell your employer you have HIV, unless you have a frontline job in the armed forces or work in a healthcare role where you perform invasive procedures.

If you work in a healthcare role, you'll need to be monitored by your occupational health team and HIV doctor to ensure you're not putting yourself and patients at risk of infection.

The Equality Act 2010 also places restrictions on the health questions employers can ask during a job application process.

Employers are allowed to ask health questions only after an offer of employment has been made to help them decide whether you can carry out tasks essential for the job.

If you're asked a question you think isn't allowed under the Equality Act 2010, you can tell the employer or the Equality and Human Rights Commission. The GOV.UK website has more information about questions an employer can ask about health and disability.

If you're an employee with HIV, you may worry that your HIV status will become public knowledge or you'll be discriminated against if you tell your employer.

On the other hand, if your boss is supportive, telling them may make it easier for adjustments to be made to your workload or for you to have time off.

The organisations listed below have lots of information, and can advise you on these and other work-related issues.

Want to know more?

Pregnancy and HIV

Advice for pregnant women

HIV treatment is available to prevent a pregnant woman passing HIV to her child.

Without treatment, there's a one in four chance your baby will become infected with HIV. With treatment, the risk is less than 1 in 100 (<1%).

Advances in treatment mean there's no increased risk of passing the virus to your baby with a normal delivery.

But insome cases, a caesarean section may still be recommended, often for reasons not related to your HIV.

Discuss the risks and benefits of each delivery method with the staff at your HIV clinic. The final decision about how your baby is delivered is yours, and staff will respect that decision.

If you have HIV, do not breastfeed your baby as the virus can be transmitted through the breast milk


If you or your partner has HIV, options may be available that allow you to conceive a child safely. You should ask your HIV doctor for advice.

If you have HIV and become pregnant, contact your HIV clinic.

This is important because:

  • some HIV treatments can be harmful to your unborn baby, so your treatment plan will need to be reviewed
  • additional medicines may be needed to prevent your baby contracting HIV

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Opportunistic infections

Infection risk

You'll be at risk of developing infections you wouldn't normally be at risk of if your immune system has been damaged by the HIV virus.

These opportunistic infections, as they're called, happen when you have a very weak immune system.

But if you take your HIV treatment, the likelihood of developing these is low.

The four main types of opportunistic infections are:

People with advanced HIV also have a higher risk of developing some forms of cancer, such as cancer of the lymphatic system (lymphoma).


Bacterial pneumonia can develop as a complication of other infections, such as flu. It can be treated with antibiotics. Left untreated, pneumonia can be fatal.

Everyone with a long-term condition such as HIV is encouraged to get a flu jab each autumn to protect against seasonal flu.

It's also recommended they have a pneumoccocal vaccination, which protects against a serious chest infection called pneumococcal pneumonia.

Pneumocystis pneumonia (PCP)

Pneumocystis pneumonia (PCP) is a fungal infection of the lungs, which can be life threatening if not treated promptly.

Before advances in HIV treatment, PCP was the leading cause of death among those with HIV in the developed world.

Symptoms of PCP include:

  • a persistent dry cough
  • shortness of breath 
  • difficulty breathing
  • fever (in some cases)

Report any symptoms of PCP straight away as the condition can suddenly worsen without warning.

PCP can be treated with antibiotics. If your CD4 count drops below 200, you may be given antibiotics to take every day until your CD4 count rises above 200.

Tuberculosis (TB)

Tuberculosis (TB) is another bacterial infection. Globally, it's one of the leading causes of death for people who are HIV positive.

The bacteria responsible for causing TB can sometimes pass from one person to another through the air. But many people who have TB aren't infectious.

TB can be treated using antibiotics, but some strains of bacteria have developed antibiotic resistance and these can be more difficult to treat.

Candidiasis (thrush)

Candidiasis is a fungal infection that's common in people living with HIV. It causes a thick, white coating to appear on the inside of the mouth, tongue, throat or vagina.

Candidiasis is rarely serious, but it can be both embarrassing and painful. It can be treated with antifungal creams and tablets.

Tell the staff at your HIV clinic if you have repeated bouts of candidiasis as it could be a sign of a low CD4 count.


People with advanced HIV have an increased risk of developing some types of cancer.

It's estimated someone with untreated late-stage HIV infection is 100 times more likely to develop certain cancers compared with someone without the condition.

The two most common cancers to affect people with HIV are:

  • lymphoma – cancer of the lymphatic system, a network of glands that makes up part of our immune system
  • Kaposi's sarcoma – this causes lesions to grow on your skin, and can also affect your internal organs

HIV treatment is important in reducing your risk of cancer and long-term conditions, such as cardiovascular and respiratory disease. If you smoke, giving up is also important in reducing this risk.

Money and financial support


If you have to stop work or work part time because of HIV, you may find it difficult to cope financially.

But you may be entitled to one or more of the following types of financial support:

Want to know more?


There are many effective ways to prevent or reduce the risk of HIV infection.  Speak to your local sexual health clinic or GP for further advice about the best way to reduce your risk.

Treatment as prevention

When someone with HIV takes effective treatment it reduces their viral load to undetectable levels.  This means the level of HIV virus in the blood is so low that it can't be detected by a test.

Having an undetectable viral load for 6 months or more means it isn't possible to pass the virus on during sex.  This is called undetectable=untransmittable (U=U), which can also be referred to as "treatment as prevention".

Want to know more?

NAM aidsmap: undetectable equals untransmittable (U=U) consensus statement


Both male condoms and female condoms are available. They come in a variety of colours, textures, materials, and flavours.

A condom is the most effective form of protection against HIV and other STIs. It can be used for vaginal and anal sex, and for oral sex performed on men.

HIV can be passed on before ejaculation through pre-come and vaginal secretions, and from the anus.

It's very important condoms are put on before any sexual contact occurs between the penis, vagina, mouth or anus.


Lubricant, or lube, is often used to enhance sexual pleasure and safety by adding moisture to either the vagina or anus during sex.

Lubricant can make sex safer by reducing the risk of vaginal or anal tears caused by dryness or friction, and can also prevent a condom tearing.

Only water-based lubricant (such as K-Y Jelly) rather than an oil-based lubricant (such as Vaseline or massage and baby oil) should be used with condoms.

Oil-based lubricants weaken the latex in condoms and can cause them to break or tear.

Sharing needles and injecting equipment

If you inject drugs, this could expose you to HIV and other viruses found in blood, such as hepatitis C.

It's important not to share needles, syringes or other injecting equipment, such as spoons and swabs, or the actual drugs or liquids used to dilute them

Many local authorities and pharmacies offer needle exchange programmes, where used needles can be exchanged for clean ones.

If you're a heroin user, consider enrolling in a methadone programme. Methadone can be taken as a liquid, so it reduces your risk of getting HIV.

A GP or drug counsellor should be able to advise you about both needle exchange programmes and methadone programmes.

If you're having a tattoo or piercing, it's important that a clean, sterilised needle is always used.

HIV prevention medication

If you're HIV negative, you may be able to take pre-exposure prophylaxis (PrEP) medication to reduce your risk of getting the virus.

PrEP is available through NHS Wales to all individuals who are assessed to be at a high risk of HIV infection.

It's available as a tablet, and is to be taken before you have sex and are exposed to HIV. You'll be able to get the medication from any sexual health clinic in Wales. 

Screening for HIV in pregnancy

If pregnant you'll be offered a blood test to check if they have HIV as part of routine antenatal screening.

If untreated, HIV can be passed from a pregnant woman to her baby during pregnancy, birth or breastfeeding.

The information on this page has been adapted by NHS Wales from original content supplied by NHS UK NHS website
Last Updated: 17/11/2023 12:37:08