Explaining HIV and AIDS (Stage 3 HIV)

HIV is a virus that targets the immune system. It damages and destroys white blood cells called CD4 T cells. Without treatment, HIV can progress to an advanced stage called stage 3 HIV, or AIDS.
The World Health Organization (WHO) estimates there were nearly 39 million people living with HIV worldwide by the end of 2022. In the United States, there were 1.2 million people living with HIV at the end of 2021.
World Health Organization (WHO)
HIV is a serious medical condition that damages the immune system. If left untreated, the virus can progress through three stages that may seriously impair a person’s quality and duration of life.
That said, due to medical advances, people with HIV who receive appropriate treatment rarely develop stage 3 HIV, or AIDS. They can manage their condition and live long, healthy lives.
As of 2022, 76% of people with HIV were receiving antiretroviral therapy.
76%
antiretroviral therapy
AIDS-related deaths have also significantly decreased by 51% since 2010.
51%
This article explores HIV and AIDS, including the symptoms, causes, and treatments.
What is HIV?
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HIV is a virus that attacks the body’s white blood cells. White blood cells circulate around the body to detect infection and faults in other cells.
HIV targets and infiltrates CD4 cells, a type of T cell. The virus uses these cells to create more copies of the virus.
In doing so, HIV destroys the cells and reduces the body’s ability to combat other infections and diseases. This increases the risk and severity of opportunistic infections and some types of cancer.
cancer
HIV that is left untreated typically develops in three stages:
three
Stage 1, acute infection: This is when people have large amounts of HIV in the blood and the body begins producing antibodies to try and kill the virus. People typically develop flu-like symptoms 2–4 weeks after contracting HIV, which may last a few weeks. This stage is when HIV is the most transmissible to other people.
2–4 weeks
Stage 2, chronic infection: HIV is still active and reproducing in the body but at a slower rate. Some people may not have symptoms, but the virus is still transmissible. This stage may last 10 years or more without treatment. If treatment begins, the virus may never progress to stage 3.
Stage 3 HIV: This is the most advanced stage of HIV, also known as AIDS. It happens when the body can no longer fight off the infection. The survival rate is around 3 years without treatment.
3 years
Learn more about the stages of HIV here.
Learn more about the stages of HIV here.
What is AIDS?
Stage 3 HIV, also called AIDS, is the most advanced stage of HIV. It typically happens if a person does not receive treatment.
Doctors diagnose it when a person’s CD4 blood count contains fewer than 200 cells per cubic millimeter, or if they have opportunistic infections.
fewer than 200 cells
opportunistic infections
The chances of HIV progressing to stage 3 vary for each person and depend on many factors, such as:
the person’s age
the body’s ability to defend against HIV
accessibility of quality healthcare
the presence of other infections
a person’s genetic resistance to certain strains of HIV
the strain of HIV, as some are drug-resistant
Learn the difference between HIV and AIDS here.
Learn the difference between HIV and AIDS here.
For more in-depth information and resources on HIV and AIDS, visit our dedicated hub.
dedicated hub
Causes
HIV is transmitted when bodily fluids containing the virus are shared between people, including:
blood
semen
pre-seminal fluid
vaginal fluids
rectal fluids
breast milk
The virus cannot be transmitted through saliva. A person cannot contract HIV through open-mouthed kissing, for example.
HIV can be transmitted through:
transmitted
anal or vaginal intercourse
sharing needles, such as for tattooing or injecting drugs
pregnancy
breastfeeding
Transmission typically occurs when people do not use barrier protection during intercourse, such as a condom. It may also happen if people with known risk factors are not taking preexposure prophylaxis (PrEP). PrEP is a treatment that aims to prevent HIV transmission.
preexposure prophylaxis (PrEP)
In extremely rare cases, HIV may be transmitted through blood transfusions.
HIV can only be transmitted through fluids that contain a certain amount of the virus. If a person has undetectable levels of HIV, the virus cannot be sexually transmitted to another person.
HIV is considered undetectable when the amount of the virus in the body is so low that a blood test cannot identify it. Some people use a shorthand to refer to the fact that undetectable levels of HIV are untransmittable: U=U.
undetectable
When the virus is undetectable, there’s effectively no risk of sexual transmission. Risk reduction is still unknown for sharing injection drug equipment. During pregnancy, the risk is 1% or less.
effectively no risk
However, a person with undetectable levels still has HIV, so it is crucial that they regularly monitor their levels with blood tests and carefully follow their recommended treatment plan.
Learn more about the early detection of HIV here.
Learn more about the early detection of HIV here.
Symptoms
Symptoms of HIV depend on the stage of the virus.
During stage 1, some people may have no symptoms for months or even years after contracting the virus. This may be why 13% of people with HIV in the United States do not know they have it.
symptoms
13%
That said, two-thirds of people with HIV develop flu-like symptoms 2–4 weeks after contracting the virus, such as:
two-thirds
fever
fever
nausea
nausea
diarrhea
diarrhea
headaches
headaches
chills
sweating, particularly at night
enlarged glands or swollen lymph nodes
swollen lymph nodes
diffuse rash
diffuse rash
fatigue
fatigue
weakness
pain, including joint pain
pain
muscle aches
sore throat
sore throat
These symptoms are collectively called “acute retroviral syndrome.” They result from the immune system fighting off the infection.
If people experience these symptoms and think they may have come into contact with HIV, they should get tested.
get tested
Some symptoms of HIV may also vary for males and females.
males
females
Learn more about the early symptoms of HIV here.
Learn more about the early symptoms of HIV here.
During stage 2, people may not have any HIV symptoms, sometimes for years.
However, the virus continues to develop and damage the immune system and organs. Without treatment, this slow process may continue for 10 years or longer, or progress faster.
10 years or longer
Taking antiretrovirals can stop this process and suppress the virus completely.
If a person with HIV does not receive effective treatment, the virus weakens the body’s ability to fight infection, exposing it to serious illnesses.
Symptoms of stage 3 HIV include:
blurred vision
dry cough
night sweats
white spots on the tongue or mouth
shortness of breath, which is called dyspnea
dyspnea
swollen glands lasting for weeks
diarrhea, which is usually persistent and chronic
diarrhea
a fever of over 100°F (37°C) that lasts for weeks
continuous fatigue
unintentional weight loss
A person with stage 3 has a significantly increased risk of developing a life threatening illness.
However, by taking other medications alongside HIV treatment, a person with stage 3 can control, prevent, and treat serious complications.
What are AIDS-defining illnesses?
Stage 3 HIV reduces the body’s ability to combat a range of infections, complications, and cancers.
Without treatment, latent infections that once caused minimal or no health problems may now pose a serious risk.
These are called opportunistic infections and may be a sign of stage 3 HIV.
opportunistic infections
Candidiasis is a fungal infection that typically occurs in the skin and nails, but it often causes serious problems in the esophagus and lower respiratory tract in people with stage 3 HIV.
Inhaling the fungus Coccidioides immitis may cause coccidioidomycosis. The infection is also referred to as valley fever.
coccidioidomycosis
This is an infection with Cryptococcus neoformansfungus. It may involve any part of the body, but the fungus usually enters the lungs and triggers pneumonia. It may also lead to swelling of the brain.
Cryptococcus gatti also causes cryptococcal infections.
also causes
Infection with the protozoan parasite Cryptosporidium can cause severe abdominal cramps and chronic, watery diarrhea for people with HIV.
Cryptosporidiosis is a common cause of diarrheal illness in people who do not have HIV. For people with a healthy immune system, symptoms typically last a couple of weeks. For people with severe or chronic diseases like stage 3 HIV, symptoms may last more than 2 months.
2 months
CMV may cause a range of diseases, including:
pneumonia
gastroenteritis
encephalitis, a brain infection
CMV retinitis is a particular concern for people with stage 3 HIV. This is an infection of the retina at the back of the eye. Because it permanently impairs eyesight, it is a medical emergency.
An infection with the herpes simplex virus (HSV) causes herpes. It is typically transmitted through anal or vaginal intercourse without a barrier method. It can cause genital or oral ulcers.
herpes simplex virus (HSV)
HSV usually resolves within a few weeks if ulcers develop in a person with a healthy immune system. In people with stage 3 HIV, severe infections may develop.
This fungal infection causes severe, pneumonia-like symptoms in people with advanced HIV. Histoplasmosis can also become progressive and widespread, affecting organs outside the respiratory system.
TB develops from the bacterium Mycobacterium tuberculosis. It may transfer through the air if a person with an active infection sneezes, coughs, or speaks. Signs and symptoms include:
include
severe lung infection
cough
chest pain
weight loss
fever
fatigue
While TB is generally considered a lung infection, it can spread to the brain and other organs.
Other types of mycobacteria, including Mycobacterium avium and Mycobacterium kansasii, are naturally present in soil and water. These mycobacteria do not generally cause infection in people who do not have underlying lung disease or compromised immune systems.
However, when a person has HIV, especially in the later stages, these infections can spread throughout the body and cause life threatening health issues.
Many pathogens may cause pneumonia, but Streptococcus pneumoniae bacteria can be among the most severe for people with HIV. A vaccine for this bacterium is available. Doctors highly recommend everyone with HIV receive it.
An infection with this fungus can cause breathlessness, a dry cough, and a high fever in people with suppressed immune systems, including some people with HIV.
This occurs when the parasite Cystoisospora belli enters the body through contaminated food and water, causing:
diarrhea
fever
vomiting
weight loss
headaches
abdominal pain
When Salmonella bacteria enter the body, they may cause typhoidal or nontyphoidal salmonella (NTS) infection.
NTS typically causes limited gastroenteritis disturbance in people with healthy immune systems.
typically
However, in people with HIV, NTS may spread to the bloodstream, causing bacteremia or septicemia, which are bloodstream infections. They may be life threatening.
Toxoplasma gondii is a parasite that inhabits warm-blooded animals, such as cats and rodents, and is present in their feces. Humans may contract toxoplasmosis by:
contract
drinking contaminated water
eating undercooked, contaminated food
ingesting the parasite accidentally, such as after changing cat litter or gardening
It can cause severe symptoms involving the:
lungs
retina
heart
liver
pancreas
brain
testes
colon
It is recommended to wear gloves while changing cat litter and thoroughly wash hands afterward to reduce the risk of contracting toxoplasmosis.
HIV can trigger encephalopathy, which is inflammation in the brain. Doctors do not fully understand the underlying mechanisms.
encephalopathy
PML stems from infection with the John Cunningham (JC) virus. The JC virus is present in many people but usually lies dormant in the kidneys.
John Cunningham (JC) virus
If a person has a weakened immune system, such as from HIV, the JC virus attacks the brain, leading to PML. It can be life threatening and cause paralysis and thinking difficulties.
paralysis
Wasting syndrome occurs when a person involuntarily loses 10% of their muscle mass through diarrhea, weakness, or a fever. Part of the weight loss may also involve fat loss.
Wasting syndrome
10%
A person with HIV may have a higher risk of various types of cancer, including:
higher risk
lymphoma, such as non-Hodgkin’s lymphoma
lymphoma
non-Hodgkin’s lymphoma
Kaposi sarcoma herpesvirus (KSHV)
Kaposi sarcoma
cervical cancer
cervical cancer
Preventing complications
Prevention is key to extending the life of a person with HIV.
It is important to manage a person’s viral load with HIV medications and take additional precautions, such as:
viral load
using barrier methods, such as condoms, to prevent other sexually transmitted infections (STIs)
sexually transmitted infections (STIs)
receiving vaccinations for potential opportunistic infections
vaccinations
identifying and limiting exposure to any environmental factors that could lead to infection
avoiding foods with a high risk of contamination, such as undercooked eggs and meat, unpasteurized dairy and fruit juices, and raw seed sprouts
not drinking water straight from a lake or river, or unfiltered tap water in certain countries
asking a doctor about relevant vaccinations and ways to limit exposure to pathogens at work, at home, and on vacation
Antibiotic, antifungal, and antiparasitic drugs can help treat opportunistic infections.
Antibiotic
antifungal
If a person’s CD4 count drops below 200, a healthcare professional may want to start medications to prevent opportunistic infections.
Read more about the possible complications of HIV here.
Read more about the possible complications of HIV here.
HIV and AIDS myths and facts
Many misconceptions circulate about HIV that contribute to the harmful stigma of the virus.
The following activities or behaviors cannot transmit HIV:
shaking hands
hugging
kissing
sneezing
touching unbroken skin
sharing a toilet
sharing towels
sharing cutlery
mouth-to-mouth resuscitation
touching the saliva, tears, feces, or urine of a person with HIV
Read more myths and facts about HIV and AIDS here.
Read more myths and facts about HIV and AIDS here.
Diagnosis
Doctors use three types of tests to detect and diagnose HIV.
three types
There is a time period between exposure to HIV and when a test can detect it. This is known as the window period. The period can vary between people and the type of test used to detect it.
window period
The three types of tests are:
Nucleic acid test (NAT): This blood test can determine how much virus is in a person’s blood. It can detect HIV the soonest after exposure, between 10 and 33 days.
10 and 33 days
Antigen/antibody tests: These test for antigens and antibodies by drawing blood from a vein or pricking a finger. They may detect HIV in a blood sample 18–90 days after exposure.
18–90 days
Rapid and self-tests: These test for antibodies in a person’s oral fluids or blood. They can detect HIV antibodies 23–90 days after exposure.
23–90 days
Healthcare professionals can test a person’s blood for HIV antibodies. Alternatively, people can use home testing kits.
antibodies
home testing kits
Anyone who thinks they may be at risk of contracting HIV can have a rapid test. If the test results are negative, the test provider usually recommends having another test within a few weeks.
If a person thinks they have had exposure to HIV within the past 72 hours, they should talk with a healthcare professional about postexposure prophylaxis (PEP), a preventive treatment.
72 hours
postexposure prophylaxis (PEP)
Learn more about the types of HIV tests available here.
Learn more about the types of HIV tests available here.
Treatment
There is currently no cure for HIV. However, treatments may help:
stop HIV from progressing
reduce the risk of transmissions
extend a person’s life expectancy
improve a person’s quality of life
Many people who take HIV treatments live long, healthy lives.
Treatments are lifelong, but medications are becoming increasingly effective and may require a person only taking one pill per day.
Anyone who may have had exposure to HIV within the past 72 hours should speak with a healthcare professional about getting PEP.
72 hours
PEP may be able to stop the infection, especially if a person takes it as soon as possible after the potential exposure.
A person takes PEP for 28 days. A doctor monitors them for HIV afterward.
PEP is not 100% effective, so it is important to use preventive techniques, such as barrier protection and safe injection practices while taking PEP.
Treating HIV involves taking antiretroviral medications that fight the infection and slow the spread of the virus.
antiretroviral
People generally take a combination of medications, called highly active antiretroviral therapy or combination antiretroviral therapy. A person might refer to the approach as HAART or cART, respectively.
There are many types of antiretrovirals, including:
Protease is an enzyme that HIV needs to replicate. Protease inhibitors bind to the enzyme and inhibit its action, preventing HIV from making copies of itself.
Protease inhibitors
Types include:
atazanavir and cobicistat (Evotaz)
lopinavir and ritonavir (Kaletra)
darunavir and cobicistat (Prezcobix)
Integrase inhibitors block the enzyme integrase, which HIV needs to infect T cells. Due to their effectiveness and limited side effects, doctors often prescribe these as part of first-line treatment.
Integrase inhibitors include:
Integrase inhibitors
dolutegravir (Tivicay)
raltegravir (Isentress)
These drugs, also called “nukes,” interfere with HIV as it tries to replicate.
Types include:
abacavir (Ziagen)
lamivudine and zidovudine (Combivir)
emtricitabine (Emtriva)
tenofovir disoproxil fumarate (Viread)
NNRTIs also make it more difficult for HIV to replicate.
Types include:
doravirine (Pifeltro)
efavirenz (Sustiva)
etravirine (Intelence)
nevirapine (Viramune)
These drugs prevent HIV from entering cells. However, doctors in the United States do not often prescribe them because they are not as effective as some other drugs.
Entry inhibitors prevent HIV from entering T cells. HIV cannot replicate if it cannot enter these cells. Entry inhibitors are also uncommon in the United States.
People often benefit from a combination of antiretroviral drugs. The right combination depends on factors specific to each person.
Read more about HIV medications here.
Read more about HIV medications here.
Many people with HIV try complementary, alternative, or herbal remedies. However, there is no evidence these options are effective.
While mineral or vitamin supplements may benefit health in other ways, it is important to discuss them with a qualified healthcare professional before taking any. Some natural products can negatively interact with HIV treatments.
can negatively interact
Learn more about alternative treatments for HIV here.
Learn more about alternative treatments for HIV here.
Prevention
The following strategies can prevent contact with HIV.
Using condoms or other barrier protection, such as dental dams, during anal, vaginal, and oral sex can drastically reduce a person’s chances of contracting HIV and other STIs.
dental dams
While people who have undergone vaginoplasty or phalloplasty may be at risk of HIV with intercourse, more studies are needed.
vaginoplasty
risk of HIV
intercourse
In their 2023 guidelines, the U.S. Preventive Services Task Force advises that doctors only approve PrEP for people with recent negative HIV tests.
2023 guidelines
The task force also approves a PrEP formation, which is a combination of tenofovir disoproxil fumarate and emtricitabine. It advises people who take PrEP to do so once a day.
The Food and Drug Administration (FDA) has also approved a second combination drug, tenofovir alafenamide/emtricitabine, as PrEP.
Food and Drug Administration (FDA)
Learn more about PrEP for transgender people here.
Learn more about PrEP for transgender people here.
Intravenous drug use is a key means of HIV transmission. Sharing needles and other drug equipment can expose a person to HIV and other viruses, such as hepatitis C.
hepatitis C
Anyone who injects any drug should do so with a clean, unused needle.
Needle exchange programs can help reduce the prevalence of HIV.
To limit the risk of HIV exposure, a person can reduce contact with blood, semen, vaginal secretions, and other bodily fluids that can carry the virus.
Frequently and thoroughly washing the skin immediately after coming into contact with bodily fluids can also reduce the risk of infection.
To prevent transmission, healthcare workers use gloves, masks, protective eyewear, face shields, and gowns when exposure to these fluids is likely. They also follow established procedures to prevent transmission.
Learn more about contracting HIV here.
Learn more about contracting HIV here.
While certain antiretrovirals can harm the fetus during pregnancy, an effective, well-managed treatment plan can prevent transmission to the fetus.
Vaginal deliveries are possible if the birthing parent with HIV manages their condition well.
It may also be possible for the virus to transmit through breast milk. The Centers for Disease Control and Prevention (CDC) does not recommend breastfeeding or chestfeeding, regardless of a person’s viral load and whether they take antiretrovirals.
Centers for Disease Control and Prevention (CDC)
It is important to discuss all the options thoroughly with a healthcare professional.
Learn more about HIV and giving birth here.
Learn more about HIV and giving birth here.
Understanding the risk factors is crucial in avoiding exposure to HIV.
Learn more about HIV and AIDS in our dedicated hub here.
Learn more about HIV and AIDS in our dedicated hub here.
Living with HIV
Many people with HIV live long, regular lives. However, due to the risk of damage to the immune system, it is important to adopt the following strategies.
Taking HIV medication as prescribed is essential. Missing even a few doses might jeopardize treatment.
A person should design a daily medication-taking routine that fits their treatment plan and schedule.
Sometimes, side effects keep people from sticking with their treatment plans. If any side effect is hard to manage, contact a healthcare professional. They can recommend a more easily tolerated drug and suggest other changes to the treatment plan.
Learn more about how HIV medications can affect the body here.
Learn more about how HIV medications can affect the body here.
Taking steps to avoid illness and other infections is key. People with HIV can exercise regularly, eat a balanced and nutritious diet, and avoid unhealthy activities, such as smoking, to boost their overall health.
It is especially important to prevent exposure to germs. This might require a person to stop eating unpasteurized foods and undercooked meats and avoid contact with animal feces and cat litter.
It is also crucial to wash hands well and regularly.
wash hands well
Learn about some ways to stop smoking here.
Learn about some ways to stop smoking here.
HIV is a lifelong condition. Regularly checking in with a healthcare team can ensure that a person’s treatment aligns with their age and any other health issues. The care team can review and adjust the treatment plan accordingly.
HIV is highly stigmatized and shrouded in misconceptions. As a result, a person may feel persecuted, isolated, or excluded.
An HIV diagnosis can be very distressing. Feelings of anxiety or depression are common. Speaking with a mental health professional or a trusted doctor can help.
anxiety
depression
The CDC provides a list of services that can help people manage the stigma and discrimination and receive additional support.
list of services
Learn more about HIV and mental health here.
Learn more about HIV and mental health here.
Frequently asked questions
HIV is a virus that attacks the body’s white blood cells. If it is left untreated, HIV may develop in three stages. AIDS refers to stage 3 HIV, which is the final and most severe stage.
A person with an HIV-positive status should speak with a doctor to get treatment as soon as possible. Although there is no cure for HIV, early treatment can help stop the virus from progressing and spreading and improve a person’s quality of life.
Approximately 13% of people with HIV do not know they have it. Some people may not have any symptoms during the first stage of HIV. However, two-thirds of people with HIV develop flu-like symptoms 2–4 weeks after contracting the virus.
13%
two-thirds
Yes, HIV is serious, but treatment can help manage it.
HIV destroys the body’s white blood cells and reduces its ability to fight off other infections and diseases. If left untreated, HIV can lead to severe complications and develop into stage 3 HIV, which is life threatening.
Summary
HIV is a viral infection that reduces the effectiveness of the immune system. Due to advances in treatment, a person with access to quality healthcare and who takes antiretroviral medication can lead a long, regular life with HIV.
HIV transmits through some bodily fluids, such as semen, vaginal secretions, and blood. The most common means of transmission in the United States are sharing needles and having sex without using barrier protection or taking PrEP.
If someone with HIV does not receive treatment, possibly because they are unaware they have HIV, the disease can progress to stage 3 HIV, or AIDS. A person with stage 3 HIV is prone to a range of infections and other health issues that can be severe and life threatening.
Sometimes, HIV causes no symptoms for years or limited symptoms that can be easily mistaken for those of the flu. Anyone in the United States who suspects recent HIV exposure can find their nearest testing facility here.
here
Read the article in Spanish.
Read the article in Spanish.