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HIV (AIDS) Symptoms and Causes

HIV, or Human Immunodeficiency Virus, is a sexually transmitted virus that attacks the specialised cells in the body that constitute the immune system. 

When the immune system is weakened enough, the body is unable to resist the infections which would not usually cause any problem in healthy people (opportunistic infections) and unable to eliminate cancer cells which would not produce a cancer in a healthy person (opportunistic cancers).

Such compromised immune system and its consequences are together described as AIDS (Acquired Immune Deficiency Syndrome).

    Instant HIV testing

    Accurate from 45 days and with results in 20 minutes, we can help you move on with your life today.

    10-Day HIV testing

    If you’re at high risk of acquiring HIV, we can look for HIV after 10 days of possible exposure.

    HIV-1 viral load test

    The HIV-1 Viral Load measures the amount of the HIV virus in your blood – only for HIV positive patients.

    HIV PrEP (before exposure)

    PrEP is a course of medicine for HIV negative people to reduce the risk of catching HIV, taken before exposure.

    HIV PEP (after exposure)

    Taken within 72 hours of exposure, this is the most effective way of preventing HIV after exposure.

    It’s important to note: 

    • You only get HIV from someone who has got HIV.
    • Even if the person has got HIV, if they are on effective treatment, they will not pass the infection to others (U=U, Undetectable = Un-transmissible).
    • Not everybody who has sexual contact with someone who is HIV positive will get HIV even if they are not on treatment.
    • You DO NOT get HIV if the other person has not got HIV.


    What are the symptoms of primary HIV infection?

    Most patients will have no symptoms of HIV.

    Some may experience flu-like symptoms 2-4 weeks after acquiring HIV infection, and this can last for a few weeks. This is the result of the multiplication of the HIV virus in large amounts – also called ‘seroconversion illness’. This may include:

    • Headache
    • Sore throat
    • Excessive fatigue
    • Chills
    • Fever
    • Muscle pain
    • Swollen lymph nodes
    • Skin rash

    However, because these symptoms can be mild and non-specific (i.e. symptoms not exclusive to HIV infection), people often do not seek medical advice until their problem has become serious enough.

    Furthermore, the symptoms of primary HIV infection are indistinguishable from other common viral infections (including Covid 19) and can mimic certain STIs, like Secondary Syphilis.

    The only way to make an early diagnosis, and thus prevent onward transmissions and prevent complications, is to recognise the potential exposure to the infection and run a HIV test.

    What are the symptoms of secondary HIV infection?

    During this stage, the HIV infection is still active in the body but reproduces at lower levels. Thus, many patients do not experience any symptoms. For this reason it is sometimes referred to as the asymptomatic phase, or latent infection.

    However, other patients experience low grade symptoms over months and years, including:

    • Fever
    • Tiredness
    • Drenching night sweats
    • Poor appetite
    • Weight loss
    • Muscle aches
    • Skin rashes and lumps
    • Diarrhoea
    • Coughing
    • Shortness of breath
    • Headache

    It’s common for patients to experience a combination of these symptoms which occur due to the effect of the HIV infection on different body systems.

    What are the symptoms of advanced HIV?

    The result of advanced HIV is AIDS (Acquired Immunodeficiency Syndrome) where the immune system is severely weakened. When this happens, the patient can acquire infections and cancers which are not seen in the general population. We call them ‘Opportunistic infections’ and ‘Opportunistic cancers’. When this happens in someone with HIV, they are said to have an AIDS-defining illness.

    The 5 most common AIDSdefining illnesses are:

    1. Pneumocystis carinii pneumonia
    2. Esophageal candidiasis
    3. Kaposi sarcoma
    4. Mycobacterium avium–intracellulare complex
    5. Cytomegalovirus retinitis.

    Furthermore, a patient with AIDS may experience the following:

    • nausea
    • vomiting
    • persistent diarrhea
    • chronic fatigue
    • rapid weight loss
    • cough and shortness of breath
    • recurring fever, chills, and night sweats
    • rashes, sores, or lesions in the mouth or nose, on the genitals, or under the skin
    • prolonged swelling of the lymph nodes in the armpits, groin, or neck
    • memory loss, confusion, or neurological disorders

    It is important to note that someone with AIDS can look and feel surprisingly well but are in fact at a great risk of sudden deterioration in their health.

    Without treatment, most patients with AIDS will die within a few years. With effective treatment, most patients with AIDS will get better and survive.

    When does HIV progress to AIDS?

    A diagnosis of AIDS is made when the CD4 T cell count falls below 200 or you have an AIDS-defining illness (see previous question).

    Without treatment, chronic HIV progresses to AIDS typically in 2-10 years after getting infection. 

    However, timely diagnosis and effective treatment will stop this progression into AIDS. Patients who already have AIDS and are recieving the correct treatment will also find their CD4 count has increased to normal range.

    Can I have HIV without any symptoms?

    Yes, most people with HIV won’t experience any symptoms until their immune system is compromised over months and years. That’s why it’s important to get tested for HIV if you suspect you may have been exposed to the virus.

    There is a small group of people with HIV whose immune system does not weaken with the passage of time. The amount of virus remains undetectable even without treatment for years, perhaps life long. Such ‘Elite Controllers’ maintain a good immune system, do not need any treatment and do not pass the infection to others.

    What are the complications of HIV?

    The complications of HIV may include:

    1. AIDS
    2. Increased risk of infections
    3. Increased risk of cancers
    4. Opportunistic infections
    5. Opportunistic cancers
    6. Risk of passing the infection to newborn by the mother during pregnancy and at the time of labour (this risk is minimised by testing during pregnancy and effective treatment)


    How do I get HIV?

    You can get HIV from:
    • Unprotected sex
    • Exposure to the HIV infected blood
      • Blood transfusion
      • Contaminated needle
    • (Rare) Mother passing the HIV virus to child during childbirth (fortunately, all pregnant women are tested for HIV during their pregnancy and therefore this is very rare in the UK).
    You can only get HIV from someone who has HIV. The question of risk becomes key as we do not always know the HIV status of your partner (and their partners).

    How do I get AIDS?

    HIV destroys CD4 T cells — white blood cells that play a large role in helping your body fight disease. The fewer CD4 T cells you have, the weaker your immune system becomes.

    You can have a HIV infection for years before it turns into AIDS. AIDS is diagnosed when the CD4 T cell count falls below 200 or you have an AIDS-defining complication.

    Who is at a greater risk of getting HIV?

    By far the greatest risk of acquiring HIV is amongst men who have sex with men and heterosexuals who have got a partner from a high prevalence country.

    Risk can also vary by sexual activity (in decreasing order of risk of transmission):

    • Anal receptive
    • Anal insertive
    • Vaginal receptive
    • Vaginal insertive
    • Oral

    These other factors can increase the risk of HIV transmission:

    • Your partner is from a country with a high prevalence of HIV
    • You have had unprotected sex with a Commercial Sex Worker (i.e. prostitute)
    • Having other STIs
    • You or your partner is Intravenous Drug User (IVDU) and share needles
    • You or your partner engages in Chemsex

    These other factors can decrease the risk of HIV transmission:

    • Use of PrEP
    • Being circumcised
    • You are a carrier of CCR5-delta 32 genetic mutation (more common in European countries)

    If you are particularly worried about the risk of getting HIV you may wish to consult our experienced clinicians who have in-depth understanding of prevalence of HIV, its transmission and prevention strategies.

    Will I pass on HIV to my family members?

    Many patients experience distressing thoughts and anxiety of passing HIV onto their family members after a potential exposure whilst waiting for test results. You can have absolute relief in the knowledge that HIV cannot be passed from any of the following:

    • kissing
    • spitting
    • 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 such as mosquitoes

    Can I get HIV from my partner who has got HIV?

    If your partner has an Undetectable HIV viral load with their effective treatment, then they cannot pass HIV to you.

    How can I prevent getting HIV?

    No action needed if:

    • Partner is HIV positive, on HIV treatment and has an undetectable viral load
    • Partner is known to be HIV negative

    Consider PEP and PrEP if:

    • Partner is HIV positive, on HIV treatment but viral load is detectable or unknown
    • Partner HIV positive, not on HIV treatment and has a detectable viral load
    • Partner HIV status is not known


    Is there a cure for HIV?

    For all practical purposes, there is presently no cure for HIV. However, HIV can be managed and those on effective treatment can live a full and flourishing life.

    — A note on the two HIV ‘cures’ in the media —

    Timothy Brown in 2007 (the ‘Berlin Patient’) and Adam Castillejo in 2019 ( “London Patient”) received a specialised bone marrow transplant for treatment of their cancers, not for HIV.

    This treatment involved replacing their immune system with stem cells from donors who had a relatively rare genetic mutation that impedes the ability of HIV to enter the cells. This mutation is called the ‘Delta 32 mutation’ (CCR5-Δ32/Δ32 genotype). In effect, the stem cell transplant replaced Timothy and Adam’s immune system with one that was resistant to the HIV and thus ‘curing them of HIV’.

    This approach is not a standard therapy for HIV due to the risk of this treatment and the relative rarity in finding suitable donors with a Delta 32 mutation. Furthermore, this treatment has failed to cure HIV in other patients treated for their cancers.

    Certainly these case reports have managed to raise hope of finding a cure one day.

    What is the treatment for HIV?

    A combination of drugs are used to completely suppress the virus and are called HAART (Highly Active Anti-retroviral Therapy) or cART (Combination Anti-Retroviral Therapy). They first got introduced in 1996, and was a turning point in the history of HIV.

    The way HAART works is by taking two drugs from one class to form the ‘backbone’ which in turn is reinforced with the addition of another drug called the ‘third agent’.

    Traditionally 3 different drugs combinations have proved most effective and popular. Few patients are on single drug therapy, and a combination of 2 drugs has become available recently. A combination of 4 drugs have been tried in the past, without any additional benefits, and are not commonly used.

    You may visit for more information.

    How successful is HIV treatment?

    A wide range of treatment options are now available to suit the needs of an individual patient.

    The aim of successful treatment is to achieve complete suppression of the virus in the blood. This is confirmed by the ‘undetectability’ of the HIV virus on a special blood test called HIV Viral Load [learn more]. More than 90% of patients in the UK who are on HAART achieve this.

    Achieving an ‘undetectable’ Viral Load has a 3-fold benefit:

    • improvement in symptoms caused by the HIV virus
    • improvement in the immune system
    • reduction in onward transmission

    What does undetectable viral load mean?

    Viral load is a measurement of the amount of virus in the blood of the person infected with HIV. This amount can vary from 0 to millions of copies of virus in per ml of blood. The higher the viral load, the more infectious the patient is and greater the adverse effect of the virus on the immune system.

    When a patient starts on the HAART therapy, the viral load drops rapidly from its baseline, and becomes undetectable within a few weeks. Tests commonly used in the UK to measure viral load have a lower limit of detection set at 20 copies/ml. When the test is not able to detect any viral load, the viral load is said to be undetectable.

    How long does it take for HIV treatment to work?

    This can depend on the combination of drugs used. Some of the currently used drugs can drop the HIV viral load rapidly and achieve undetectability as soon as 4 weeks after starting treatment. Other drugs can take between 3-4 months to reach an undetectable HIV viral load.

    When should I start HIV medication?

    HIV therapy is started as soon as possible after a HIV diagnosis, to achieve the best outcome.

    In the past, HIV treatment used to be recommended after CD4 T cell count, a marker of the immune system, dropped below a certain level.

    The only group where HIV therapy is not needed are Elite controllers (link to elsewhere for details).

    Are there any side effects?

    Earlier generations of HAART  had lots of side effects, making it difficult to take these medications on a long term basis for many patients. However, currently used drugs to treat HIV are very well tolerated, and cause minimal or no side effects in most patients. If a patient experiences serious or intolerable side effects, other drug choices are available to try.

    Can I become resistant to HIV medication?

    Resistance to HIV drugs can occasionally develop in patients who do not take their medications regularly. Development of resistance to one or more HIV drugs results in virus becoming detectable in blood and the weakening of the immune system.

    To prevent drug resistance from developing:

    1. Emphasis is given on adherence to these medications by HIV doctors.
    2. A HIV Genotype Resistance test is done to select correct medications before starting therapy.
    3. Combining 3 different HIV drugs together also prevents the development of drug resistance.
    4. Patients on HIV therapy get their HIV viral load test done every 3-6 months. Regular tests allow failing drug therapy to be identified on time, and for preventive action to be taken.

    What happens if I develop a resistance to HIV medication?

    If you develop resistance to a HIV drug, you will be switched to a new set of medications without resistance.

    As there are more than 20 drugs from 6 different classes currently in routine use to treat HIV, a HIV Genotype Resistance test will be carried out to guide the selection of the drugs that will work.

    Can I take this with other medications?

    Most medications for various medical conditions can be taken at the same time as HIV drugs. 

    However, some medications interact with certain HIV drugs, and this is taken into consideration while prescribing HIV drugs as well as other drugs. This will be discussed with your HIV doctor.

    Where can I get treatment for HIV?

    NHS provides treatment for HIV through Sexual Health Clinics. The service is confidential and free of charge.

    Does my partner also need HIV treatment?

    Your partner will only need HIV treatment if they also test positive for HIV.

    It is important to note that not everyone who has sex with someone with HIV will get infected with the virus.

    Can I have sex again?

    We recommend having unprotected sex when your HIV treatment is working successfully, as to eliminate the risk of passing the infection to a sexual partner. This will be when the level of the HIV virus is undetectable in your blood, as ascertained by a HIV Viral Load test.

    In the meantime, you should use a condom.


    Here are images of some cases of HIV (before receiving treatment).

    Please be advised that the images are highly graphic in nature.

    More coming soon

    Page reviewed by Dr. Manoj Malu (Clinical Director)

    Last reviewed date: 3 March 2020
    Next review due: 3 March 2023

    Whilst this content is written and reviewed by sexual health specialists, it is for general guidance only. It is not intended to replace the advice of your clinician.