HIV infection

HIV stands for human immunodeficiency virus. It is a virus that targets and gradually weakens the body's immune system, which is the network of cells and organs that fights off infections. In particular, HIV attacks a type of white blood cell called the CD4 cell (sometimes written CD4+ T-cell). These cells act like coordinators of the immune response. As HIV copies itself, it damages these cells, so over time the body finds it harder to defend itself against illnesses it would normally cope with easily.

It helps to understand the difference between HIV and AIDS, because people often use the two words as if they mean the same thing. HIV is the virus. AIDS (acquired immune deficiency syndrome) is the name given to the most advanced stage of untreated HIV, when the immune system has been seriously weakened and certain serious infections or cancers appear. Today AIDS is often called late-stage or advanced HIV. Importantly, not everyone with HIV develops AIDS. In countries with good access to treatment, most people being treated for HIV never reach that stage.

There is currently no cure that removes HIV from the body, and once someone has HIV they have it for life. But this is no longer the picture many people imagine. Modern medicines can keep the virus under such tight control that it stops damaging the immune system and cannot be passed on through sex. In that sense, HIV has become a chronic (long-term) condition that can be managed day to day, much like diabetes or high blood pressure.

There are two main types of the virus. HIV-1 is by far the most common type worldwide and is what most people mean when they say HIV. HIV-2 is much less common, found mainly in West Africa, and tends to progress more slowly; it also responds differently to some medicines, which is why correct testing matters.

Rather than "subtypes" in the way some other conditions have them, HIV is usually described in three stages, based on how far it has progressed:

• Stage 1 - acute (early) infection. In the first weeks after the virus enters the body, it multiplies rapidly and the amount of virus in the blood (the viral load) is very high. Many people feel a short flu-like illness during this time, and a person is especially likely to pass the virus on at this stage.
• Stage 2 - chronic (clinical latency) infection. The virus is still active and still reproducing, but more slowly. Many people feel completely well and have no symptoms, sometimes for a decade or longer if untreated. With effective treatment, people can stay in a healthy, stable state indefinitely.
• Stage 3 - AIDS (advanced HIV). This is diagnosed when the immune system is badly damaged - specifically when the CD4 count falls below 200 cells per cubic millimetre of blood (a healthy count is roughly 500 to 1,500), or when certain serious "opportunistic" infections or cancers develop. With modern treatment, this stage is increasingly uncommon.

These stages are a map of what can happen without treatment. They are not a fixed timetable, and treatment can stop progression and even improve the immune system's strength.

HIV is caused by the virus passing from one person to another through specific body fluids: blood, semen, pre-seminal fluid, rectal fluids, vaginal fluids and breast milk. For the virus to spread, one of these fluids from a person who has HIV (and whose virus is not fully suppressed by treatment) has to enter the bloodstream or come into contact with certain body tissues of another person.

The main ways this happens are:

• Sex without a condom (anal, vaginal or, less commonly, oral) with someone who has a detectable viral load.
• Sharing needles, syringes or other equipment used to inject drugs.
• From parent to baby during pregnancy, childbirth or breastfeeding - although this is now largely preventable with treatment.
• Less commonly, through blood transfusions or medical equipment in places where blood is not screened and equipment is not sterile.

It is just as important to know how HIV is not spread, because fear of casual contact causes a great deal of unnecessary worry and stigma. You cannot catch HIV from hugging, kissing, shaking hands, sharing food or drinks, toilet seats, swimming pools, insect bites, sweat, tears, coughs or sneezes, or everyday household contact.

Some circumstances raise the chance of exposure: having sex without condoms or PrEP (a preventive medicine described later), having another sexually transmitted infection, sharing injecting equipment, and being in a community where HIV is more common. Risk factors describe situations, not people - HIV can affect anyone, of any age, gender or background.

One of the most important things to understand about HIV is that you cannot tell from how you feel whether you have it. Many people have no symptoms for years and feel perfectly well, while the virus quietly affects the immune system. This is exactly why testing, not waiting for symptoms, is the way HIV is found.

In the first two to four weeks after infection (around 2 to 6 weeks), some people get a short, flu-like illness sometimes called seroconversion illness. Possible signs include:

• A high temperature (fever), chills or night sweats
• A sore throat
• Swollen glands (lymph nodes), often in the neck
• A body rash
• Aching muscles and joints, tiredness
• Mouth ulcers

These symptoms are easy to mistake for ordinary flu or another infection, and they pass on their own in a week or two. Because they are so common and non-specific, they are not a reliable way to diagnose HIV - but if you have had a possible exposure and develop them, it is a good reason to test.

If HIV is left untreated for years and the immune system becomes very weak, later signs can include persistent tiredness, unexplained weight loss, ongoing diarrhoea, recurring fevers and night sweats, and infections that keep coming back.

When to seek advice: Talk to a doctor or sexual health clinic if you think you may have been exposed to HIV, if you have ongoing unexplained symptoms like those above, or simply if you have never been tested. If a possible exposure happened within the last 72 hours, contact a clinic or emergency service urgently, because an emergency preventive medicine (PEP) may stop infection if started quickly.

Because HIV often causes no symptoms for a long time, testing is the only way to know your status, and finding it early makes a real difference to long-term health. Health authorities recommend that everyone is tested at least once as part of routine care - in the United States, the recommendation is that everyone aged 13 to 64 be tested at least once. People with ongoing risk (for example, those who have new or multiple sexual partners, who inject drugs, or whose partner has HIV) are advised to test more often, such as at least once a year or more frequently.

Testing in pregnancy is a standard part of antenatal care in many countries, because finding and treating HIV during pregnancy almost completely prevents passing it to the baby.

Testing is straightforward, confidential and widely available - through clinics, family doctors, community services and home self-test kits. Knowing your status early means treatment can start before the immune system is harmed, which is linked to the best long-term outcomes. A negative result can also be reassuring and is a chance to learn about prevention options such as PrEP.

HIV is diagnosed with a simple test on a small sample of blood (from a vein or a finger-prick) or, for some tests, oral fluid swabbed from inside the mouth. There are three main kinds of test, and they differ mainly in how soon after exposure they can detect infection - this gap is called the window period:

• Antigen/antibody test. This looks for both HIV antibodies (proteins the immune system makes) and a part of the virus called the p24 antigen. A laboratory blood test of this type can usually detect HIV about 18 to 45 days after exposure; rapid finger-prick versions may take a little longer.
• Antibody test. This looks only for antibodies and is used in most rapid tests and in the self-test kits you can use at home, with results in 30 minutes or less. It can typically detect HIV 23 to 90 days after exposure.
• Nucleic acid test (NAT). This looks for the virus itself in the blood and can detect it earliest, about 10 to 33 days after exposure. It is usually used for people with a recent high-risk exposure and early symptoms, or to confirm other results.

A first positive ("reactive") result is always confirmed with a follow-up test before a diagnosis is made, so a single screening result is not the final word. If you test soon after a possible exposure and the result is negative, you may be asked to test again after the window period has passed.

If HIV is diagnosed, the doctor will order further blood tests to guide care - especially the CD4 count (a measure of immune strength) and the viral load (how much virus is in the blood). These two numbers, repeated over time, show how well treatment is working.

The standard treatment for HIV is antiretroviral therapy, usually shortened to ART. ART is a combination of medicines that stop the virus from copying itself. It does not remove HIV from the body, but it lowers the amount of virus to such low levels that standard tests can no longer detect it - a state called an undetectable viral load. Once the virus is suppressed, the immune system can recover and stay strong, and the person stays well.

ART medicines come in several families (classes), each blocking the virus at a different step. These include nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), integrase strand transfer inhibitors (INSTIs), protease inhibitors (PIs), and newer classes such as entry, fusion and capsid inhibitors. For most people starting treatment today, guidelines recommend a combination built around an integrase inhibitor plus two NRTIs. Many regimens are now a single tablet once a day, which makes treatment much simpler than in the past.

Current guidance is to start ART as soon as possible after diagnosis, whatever the CD4 count, because earlier treatment protects health and prevents transmission. There are also long-acting injectable options for some people - for example a combination of cabotegravir and rilpivirine given by injection every one or two months - which can replace daily pills for those who are already stable.

HIV care is delivered by a multidisciplinary team. This usually includes an infectious-disease or HIV specialist doctor, specialist nurses, a pharmacist who checks for interactions with other medicines, and counsellors or psychologists for emotional support. Supportive care also covers vaccinations, screening and treatment of any other infections, mental-health support, and help with sticking to treatment. Treatment is lifelong, and taking medicines consistently every day is the single most important factor in keeping the virus controlled.

The outlook for HIV has changed dramatically over the past few decades, and this is genuinely good news. With early diagnosis and effective treatment, most people with HIV can expect to live a long and healthy life, with a life expectancy approaching that of people without HIV. Research from large patient groups suggests that people who start treatment promptly, take it consistently, and reach a good CD4 count and an undetectable viral load can expect a near-normal lifespan.

The figures above come from population studies and describe groups of people, not any one individual. Your own outlook depends on several things - especially how early treatment starts, the CD4 count at diagnosis, how consistently medicines are taken, and other aspects of general health. They are not a prediction for any single person. The clearest message from the evidence is that starting treatment early and staying on it is strongly linked to the best long-term health.

Without treatment, HIV tends to progress over years to advanced disease, which is why testing and early care matter so much. With treatment, the day-to-day reality for most people is simply taking a tablet (or having a periodic injection), attending regular check-ups, and otherwise getting on with normal life - work, relationships, travel and, for many, parenthood.

Living well with HIV centres on a steady, manageable routine. After treatment begins, the viral load usually falls to undetectable levels within about six months. From then on, life settles into regular monitoring - typically blood tests a few times a year to check the viral load and CD4 count, and reviews with the HIV team to make sure the chosen medicines suit you and are not causing side effects.

A central, reassuring fact is U=U, which stands for Undetectable = Untransmittable. This is the evidence-based finding that a person on effective treatment who keeps an undetectable viral load cannot pass HIV to a sexual partner. U=U has transformed how people can think about relationships, intimacy and having children.

Day-to-day, the same things that keep anyone healthy matter here too: not smoking, moderate alcohol, regular activity, a balanced diet, vaccinations, and looking after mental health. Because living with a long-term condition - and dealing with stigma - can affect mood and wellbeing, support from counsellors, peer groups and patient organisations is a valuable part of care. Telling the HIV team about all other medicines and supplements is important, since some can interact with ART.

If you are considering arranging HIV care abroad, it helps to understand what shapes the overall cost and how to prepare, so you can ask the right questions and get a clear, personalised estimate. We do not publish fixed prices here, because the right plan - and therefore the cost - depends on your individual situation.

Factors that typically influence cost include:

• The tests needed at the start and over time (confirmatory HIV testing, CD4 count, viral load, resistance testing, and screening for other infections such as hepatitis and tuberculosis).
• The medicines prescribed - which specific antiretroviral regimen is chosen, and whether it is a daily tablet or a long-acting injectable.
• The intensity of monitoring and follow-up, including how often you are reviewed and which specialists are involved.
• Whether you need treatment for other conditions or co-infections at the same time.
• Practical elements such as consultations, interpreter support, accommodation and travel, and how follow-up will continue after you return home.

To prepare, gather and bring copies of your medical records: any previous HIV test results, recent CD4 and viral load results, a list of all medicines you take (including doses), records of any past treatments and resistance tests, your vaccination history, and details of other health conditions. Having these ready helps the team plan accurately and avoid repeating tests. The best next step is to request a free consultation for a personalised estimate based on your records and needs. HIV care is lifelong, so it is also wise to plan how monitoring and prescriptions will continue in your home country between visits.

Turkiye (Turkey) has become a well-known destination for international patients, with large hospitals, experienced specialists and services geared towards people travelling from abroad, often including interpreter support and help with logistics. For a condition like HIV, what matters most is not the location itself but the quality and continuity of specialist care.

When choosing where to receive care, it is sensible to verify some practical things rather than relying on marketing claims:

• Accreditation and standards. Look for hospitals with recognised quality accreditation and proper laboratory facilities for HIV monitoring.
• A genuine specialist team. Care should be led by infectious-disease or HIV specialists, supported by specialist nurses, pharmacists and counsellors - the multidisciplinary team described earlier.
• Confidentiality and respect. Ask how your privacy is protected and how the service handles HIV care sensitively.
• Access to medicines and testing. Confirm that the specific antiretroviral regimens and laboratory tests (CD4, viral load, resistance testing) you may need are available.
• Follow-up and communication. Clarify how results, prescriptions and ongoing monitoring will be shared with you and, where relevant, with your doctor at home, and whether records are provided in a language you understand.

A reputable centre will be transparent about what is and is not included, will encourage you to keep your own copies of records, and will support continuity of your lifelong treatment rather than treating your visit as a one-off.

HIV is highly preventable, and the options today are more effective than ever. Key prevention tools include:

• Condoms. Used correctly, condoms are a highly effective way to prevent HIV and other sexually transmitted infections.
• PrEP (pre-exposure prophylaxis). This is medicine taken by people who do not have HIV to protect themselves before possible exposure. It is very effective when used as prescribed and comes as a daily tablet, and now also as long-acting injections. A twice-yearly injectable option, lenacapavir, was approved in the United States in 2025 and showed very high protection in clinical trials.
• PEP (post-exposure prophylaxis). This is emergency medicine for someone who may have just been exposed to HIV. It must be started within 72 hours of exposure and is taken for 28 days.
• Treatment as prevention (U=U). When a person with HIV is on effective treatment with an undetectable viral load, they cannot pass the virus on through sex.
• Sterile injecting equipment for people who inject drugs, available through needle and syringe programmes.
• Treatment in pregnancy, which dramatically reduces the chance of passing HIV to a baby.

For anyone living with HIV, self-care means taking treatment consistently, attending regular check-ups, keeping up with vaccinations and general health screening, and reaching out for emotional and peer support when needed. Whatever your situation, a qualified specialist or sexual-health clinic can talk through which prevention or treatment options fit you best.