Acquired immunodeficiency syndrome (AIDS), is an ongoing, also called chronic, condition. It's caused by the human immunodeficiency virus, also called HIV. HIV damages the immune system so that the body is less able to fight infection and disease. If HIV isn't treated, it can take years before it weakens the immune system enough to become AIDS. Thanks to treatment, most people in the U.S. don't get AIDS.

HIV is spread through contact with genitals, such as during sex without a condom. This type of infection is called a sexually transmitted infection, also called an STI. HIV also is spread through contact with blood, such as when people share needles or syringes. It is also possible for a person with untreated HIV to spread the virus to a child during pregnancy, childbirth or breastfeeding.

There's no cure for HIV/ AIDS. But medicines can control the infection and keep the disease from getting worse. Antiviral treatments for HIV have reduced AIDS deaths around the world. There's an ongoing effort to make ways to prevent and treat HIV/ AIDS more available in resource-poor countries.

The symptoms of HIV and AIDS vary depending on the person and the phase of infection.

Primary infection, also called acute HIV

Some people infected by HIV get a flu-like illness within 2 to 4 weeks after the virus enters the body. This stage may last a few days to several weeks. Some people have no symptoms during this stage.

Possible symptoms include:

• Fever.
• Headache.
• Muscle aches and joint pain.
• Rash.
• Sore throat and painful mouth sores.
• Swollen lymph glands, also called nodes, mainly on the neck.
• Diarrhea.
• Weight loss.
• Cough.
• Night sweats.

These symptoms can be so mild that you might not notice them. However, the amount of virus in your bloodstream, called viral load, is high at this time. As a result, the infection spreads to others more easily during primary infection than during the next stage.

Clinical latent infection, also called chronic HIV

In this stage of infection, HIV is still in the body and cells of the immune system, called white blood cells. But during this time, many people don't have symptoms or the infections that HIV can cause.

This stage can last for many years for people who aren't getting antiretroviral therapy, also called ART. Some people get more-severe disease much sooner.

Symptomatic HIV infection

As the virus continues to multiply and destroy immune cells, you may get mild infections or long-term symptoms such as:

• Fever.
• Fatigue.
• Swollen lymph glands, which are often one of the first symptoms of HIV infection.
• Diarrhea.
• Weight loss.
• Oral yeast infection, also called thrush.
• Shingles, also called herpes zoster.
• Pneumonia.

Progression to AIDS

Better antiviral treatments have greatly decreased deaths from AIDS worldwide. Thanks to these lifesaving treatments, most people with HIV in the U.S. today don't get AIDS. Untreated, HIV most often turns into AIDS in about 8 to 10 years.

Having AIDS means your immune system is very damaged. People with AIDS are more likely to develop diseases they wouldn't get if they had healthy immune systems. These are called opportunistic infections or opportunistic cancers. Some people get opportunistic infections during the acute stage of the disease.

The symptoms of some of these infections may include:

• Sweats.
• Chills.
• Fever that keeps coming back.
• Ongoing diarrhea.
• Swollen lymph glands.
• Constant white spots or lesions on the tongue or in the mouth.
• Constant fatigue.
• Weakness.
• Rapid weight loss.
• Skin rashes or bumps.

When to see a doctor

If you think you may have been infected with HIV or are at risk of contracting the virus, see a healthcare professional as soon as you can.

HIV is caused by a virus. It can spread through sexual contact, shooting of illicit drugs or use of shared needles, and contact with infected blood. It also can spread from parent to child during pregnancy, childbirth or breastfeeding.

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

How does HIV become AIDS?

You can have an HIV infection with few or no symptoms for years before it turns into AIDS. AIDS is diagnosed when the CD4 T cell count falls below 200 or you have a complication you get only if you have AIDS, such as a serious infection or cancer.

How HIV spreads

You can get infected with HIV if infected blood, semen or fluids from a vagina enter your body. This can happen when you:

• Have sex. You may become infected if you have vaginal or anal sex with an infected partner. Oral sex carries less risk. The virus can enter your body through mouth sores or small tears that can happen in the rectum or vagina during sex.
• Share needles to inject illicit drugs. Sharing needles and syringes that have been infected puts you at high risk of HIV and other infectious diseases, such as hepatitis.
• Have a blood transfusion. Sometimes the virus may be transmitted through blood from a donor. Hospitals and blood banks screen the blood supply for HIV. So this risk is small in places where these precautions are taken. The risk may be higher in resource-poor countries that are not able to screen all donated blood.
• Have a pregnancy, give birth or breastfeed. Pregnant people who have HIV can pass the virus to their babies. People who are HIV positive and get treatment for the infection during pregnancy can greatly lower the risk to their babies.

How HIV doesn't spread

You can't become infected with HIV through casual contact. That means you can't catch HIV or get AIDS by hugging, kissing, dancing or shaking hands with someone who has the infection.

HIV isn't spread through air, water or insect bites. You can't get HIV by donating blood.

Anyone of any age, race, sex or sexual orientation can have HIV/ AIDS. However, you're at greatest risk of HIV/ AIDS if you:

• Have unprotected sex. Use a new latex or polyurethane condom every time you have sex. Anal sex is riskier than is vaginal sex. Your risk of HIV increases if you have more than one sexual partner.
• Have an STI. Many STIs cause open sores on the genitals. These sores allow HIV to enter the body.
• Inject illicit drugs. If you share needles and syringes, you can be exposed to infected blood.

HIV infection weakens your immune system. The infection makes you much more likely to get many infections and certain types of cancers.

Infections common to HIV/AIDS

• Pneumocystis pneumonia, also called PCP. This fungal infection can cause severe illness. It doesn't happen as often in the U.S. because of treatments for HIV/ AIDS. But PCP is still the most common cause of pneumonia in people infected with HIV.
• Candidiasis, also called thrush. Candidiasis is a common HIV-related infection. It causes a thick, white coating on the mouth, tongue, esophagus or vagina.
• Tuberculosis, also called TB. TB is a common opportunistic infection linked to HIV. Worldwide, TB is a leading cause of death among people with AIDS. It's less common in the U.S. thanks to the wide use of HIV medicines.
• Cytomegalovirus. This common herpes virus is passed in body fluids such as saliva, blood, urine, semen and breast milk. A healthy immune system makes the virus inactive, but it stays in the body. If the immune system weakens, the virus becomes active, causing damage to the eyes, digestive system, lungs or other organs.
• Cryptococcal meningitis. Meningitis is swelling and irritation, called inflammation, of the membranes and fluid around the brain and spinal cord, called meninges. Cryptococcal meningitis is a common central nervous system infection linked to HIV. A fungus found in soil causes it.

• Toxoplasmosis. This infection is caused by Toxoplasma gondii, a parasite spread primarily by cats. Infected cats pass the parasites in their stools. The parasites then can spread to other animals and humans.

  Toxoplasmosis can cause heart disease. Seizures happen when it spreads to the brain. And it can be fatal.

Cancers common to HIV/AIDS

• Lymphoma. This cancer starts in the white blood cells. The most common early sign is painless swelling of the lymph nodes most often in the neck, armpit or groin.
• Kaposi sarcoma. This is a tumor of the blood vessel walls. Kaposi sarcoma most often appears as pink, red or purple sores called lesions on the skin and in the mouth in people with white skin. In people with Black or brown skin, the lesions may look dark brown or black. Kaposi sarcoma also can affect the internal organs, including the lungs and organs in the digestive system.
• Human papillomavirus (HPV)-related cancers. These are cancers caused by HPV infection. They include anal, oral and cervical cancers.

Other complications

• Wasting syndrome. Untreated HIV/ AIDS can cause a great deal of weight loss. Diarrhea, weakness and fever often happen with the weight loss.
• Brain and nervous system, called neurological, complications. HIV can cause neurological symptoms such as confusion, forgetfulness, depression, anxiety and difficulty walking. HIV-associated neurological conditions can range from mild symptoms of behavior changes and reduced mental functioning to severe dementia causing weakness and not being able to function.
• Kidney disease. HIV-associated nephropathy (HIVAN) is swelling and irritation, called inflammation, of the tiny filters in the kidneys. These filters remove excess fluid and waste from the blood and pass them to the urine. Kidney disease most often affects Black and Hispanic people.
• Liver disease. Liver disease also is a major complication, mainly in people who also have hepatitis B or hepatitis C.

There's no vaccine to prevent HIV infection and no cure for HIV/ AIDS. But you can protect yourself and others from infection.

To help prevent the spread of HIV:

• Consider preexposure prophylaxis, also called PrEP. There are two PrEP medicines taken by mouth, also called oral, and one PrEP medicine given in the form of a shot, called injectable. The oral medicines are emtricitabine-tenofovir disoproxil fumarate (Truvada) and emtricitabine-tenofovir alafenamide fumarate (Descovy). The injectable medicine is called cabotegravir (Apretude). PrEP can reduce the risk of sexually transmitted HIV infection in people at very high risk.

  PrEP can reduce the risk of getting HIV from sex by about 99% and from injecting drugs by at least 74%, according to the Centers for Disease Control and Prevention. Descovy hasn't been studied in people who have sex by having a penis put into their vaginas, called receptive vaginal sex.

  Cabotegravir (Apretude) is the first U.S. Food and Drug Administration-approved PrEP that can be given as a shot to reduce the risk of sexually transmitted HIV infection in people at very high risk. A healthcare professional gives the shot. After two once-monthly shots, Apretude is given every two months. The shot is an option in place of a daily PrEP pill.

  Your healthcare professional prescribes these medicines to prevent HIV only to people who don't already have HIV infection. You need an HIV test before you start taking any PrEP. You need to take the test every three months for the pills or before each shot for as long as you take PrEP.

  You need to take the pills every day or closely follow the shot schedule. You still need to practice safe sex to protect against other STIs. If you have hepatitis B, you should see an infectious disease or liver specialist before beginning PrEP therapy.

• Use treatment as prevention, also called TasP. If you have HIV, taking HIV medicines can keep your partner from getting infected with the virus. If your blood tests show no virus, that means your viral load can't be detected. Then you won't transmit the virus to anyone else through sex.

  If you use TasP, you must take your medicines exactly as prescribed and get regular checkups.

• Use post-exposure prophylaxis, also called PEP, if you've been exposed to HIV. If you think you've been exposed through sex, through needles or in the workplace, contact your healthcare professional or go to an emergency room. Taking PEP as soon as you can within the first 72 hours can greatly reduce your risk of getting HIV. You need to take the medicine for 28 days.

• Use a new condom every time you have anal or vaginal sex. Both male and female condoms are available. If you use a lubricant, make sure it's water based. Oil-based lubricants can weaken condoms and cause them to break.

  During oral sex, use a cut-open condom or a piece of medical-grade latex called a dental dam without a lubricant.

• Tell your sexual partners you have HIV. It's important to tell all your current and past sexual partners that you're HIV positive. They need to be tested.
• Use clean needles. If you use needles to inject illicit drugs, make sure the needles are sterile. Don't share them. Use needle-exchange programs in your community. Seek help for your drug use.
• If you're pregnant, get medical care right away. You can pass HIV to your baby. But if you get treatment during pregnancy, you can lessen your baby's risk greatly.
• Consider male circumcision. Studies show that removing the foreskin from the penis, called circumcision, can help reduce the risk of getting HIV infection.

HIV can be diagnosed through blood or saliva testing. Tests include:

• Antigen-antibody tests. These tests most often use blood from a vein. Antigens are substances on the HIV virus itself. They most often show up in the blood within a few weeks after being exposed to HIV.

  The immune system makes antibodies when it's exposed to HIV. It can take weeks to months for antibodies to show up in blood. You may not show a positive result on an antigen-antibody test until 2 to 6 weeks after exposure to HIV.

• Antibody tests. These tests look for antibodies to HIV in blood or saliva. Most rapid HIV tests are antibody tests. This includes self-tests done at home. You may not show a positive result on an antibody test until 3 to 12 weeks after you've been exposed to HIV.

• Nucleic acid tests (NATs). These tests look for the virus in your blood, called viral load. They use blood from a vein.

  If you might have been exposed to HIV within the past few weeks, your healthcare professional may suggest NAT. NAT is the first test to become positive after exposure to HIV.

Talk with your healthcare professional about which HIV test is right for you. If any of these tests are negative, you may need a follow-up test weeks to months later to confirm the results.

Tests to stage disease and treatment

If you've been diagnosed with HIV, find a specialist trained in diagnosing and treating HIV to help you:

• Decide whether you need other tests.
• Find which HIV antiretroviral therapy, also called ART, is best for you.
• Watch your progress and work with you to manage your health.

If you get a diagnosis of HIV/ AIDS, tests can help your healthcare professional learn the stage of your disease and the best treatment, including:

• CD4 T cell count. CD4 T cells are white blood cells that HIV targets and destroys. Even if you have no symptoms, HIV infection becomes AIDS when your CD4 T cell count dips below 200.
• Viral load, also called HIV RNA. This test measures the amount of virus in your blood. After starting HIV treatment, the goal is to have a viral load so low that it doesn't show up on the test, called undetectable. This greatly reduces your chances of opportunistic infection and other HIV-related complications.
• Medicine resistance. Some strains of HIV are resistant to medicines. This test helps your healthcare professional know if your form of the virus has resistance. This guides treatment decisions.

Tests for complications

Your healthcare professional also might order lab tests to check for other infections or complications, including:

• Tuberculosis.
• Hepatitis B or hepatitis C virus infection.
• STIs.
• Liver or kidney damage.
• Urinary tract infection.
• Cervical and anal cancer.
• Cytomegalovirus.
• Toxoplasmosis.

There's no cure for HIV/ AIDS. Once you have the infection, your body can't get rid of it. But there are medicines that can control HIV and prevent complications.

Everyone diagnosed with HIV should take antiretroviral therapy medicines, also called ART. This is true no matter what stage the disease is in or what the complications are.

ART is usually a mix of two or more medicines from several classes. This approach has the best chance of lowering the amount of HIV in the blood. There are many ART options that mix more than one HIV medicine into a single pill, taken once daily.

Each class of medicines blocks the virus in different ways. Treatment involves mixing medicines from different classes to:

• Account for medicine resistance, called viral genotype.
• Keep from creating new medicine-resistant strains of HIV.
• Suppress the virus in the blood as much as possible.

Two medicines from one class, plus a third medicine from another class, are most often used.

The classes of anti- HIV medicines include the following:

• Non-nucleoside reverse transcriptase inhibitors (NNRTIs) turn off a protein needed by HIV to make copies of itself.

  Examples include efavirenz, rilpivirine (Edurant) and doravirine (Pifeltro).

• Nucleoside or nucleotide reverse transcriptase inhibitors (NRTIs) are faulty versions of the building blocks that HIV needs to make copies of itself.

  Examples include abacavir (Ziagen), tenofovir disoproxil fumarate (Viread), emtricitabine (Emtriva), lamivudine (Epivir) and zidovudine (Retrovir). Retrovir is no longer suggested for routine use in the U.S. because of high rates of toxic effects.

  Mixes of medicines also are available, such as emtricitabine-tenofovir disoproxil fumarate (Truvada) and emtricitabine-tenofovir alafenamide fumarate (Descovy).

• Protease inhibitors (PIs) make HIV protease inactive. HIV protease is another protein that HIV needs to make copies of itself.

  Examples include atazanavir (Reyataz), darunavir (Prezista) and lopinavir-ritonavir (Kaletra).

• Integrase inhibitors stop the action of a protein called integrase. HIV uses integrase to put its genetic material into CD4 T cells.

  Examples include bictegravir sodium-emtricitabine-tenofovir alafenamide fumarate (Biktarvy), raltegravir (Isentress), dolutegravir (Tivicay) and cabotegravir (Vocabria).

• Entry or fusion inhibitors block HIV's entry into CD4 T cells.

  Examples include enfuvirtide (Fuzeon) and maraviroc (Selzentry). Newer medicines include ibalizumab-uiyk (Trogarzo) and fostemsavir (Rukobia).

Starting and staying on treatment

Everyone with HIV infection, no matter what the CD4 T cell count or symptoms are, should be offered antiviral medicine.

Staying on ART that keeps your HIV viral load in the blood from being detected is the best way for you to stay healthy.

For ART to work, you must take the medicines as prescribed. Don't miss or skip doses. Staying on ART with an undetectable viral load helps:

• Keep your immune system strong.
• Lower your chances of getting an infection.
• Lower your chances of getting treatment-resistant HIV.
• Lower your chances of giving HIV to other people.

Staying on HIV therapy can be hard. Talk to your healthcare professional about possible side effects, trouble you have taking medicines, and any mental health or substance use issues that may make it hard for you to stay on ART.

Have regular follow-up appointments with your health professional to check your health and response to treatment. Let your health professional know right away if you have problems with HIV therapy. Then you can work together to find ways to deal with those issues.

Treatment side effects

Treatment side effects can include:

• Nausea, vomiting or diarrhea.
• Heart disease.
• Kidney and liver damage.
• Weakened bones or bone loss.
• Cholesterol levels that are not typical.
• Higher blood sugar.
• Problems with thinking, emotions and sleep.

Treatment for age-related diseases

Some health issues that are a part of aging may be harder to manage if you have HIV. Some medicines that are common for age-related heart, bone or metabolic conditions, for example, may not mix well with anti- HIV medicines. Talk with your healthcare professional about your other health conditions and the medicines you take for them.

If another health professional prescribes a medicine for another condition, let that health professional know about your HIV therapy. Then the health professional can make sure there are no problems with taking the medicines together.

Treatment response

Your healthcare professional will watch your viral load and CD4 T cell counts to see your response to HIV treatment. The first check is at 4 to 6 weeks. After that, you see your health professional every 3 to 6 months.

Treatment should lower your viral load so that can't be found in the blood. That doesn't mean your HIV is gone. Even if it can't be found in the blood, HIV is still in your body.

Besides getting medical treatment, you need to take an active role in your own care. The following may help you stay healthy longer:

• Eat healthy foods. Fresh fruits and vegetables, whole grains, and lean protein help keep you strong, give you more energy and support your immune system. Eat enough calories to keep your weight stable.
• Avoid raw meat, eggs and more. Foodborne illnesses can be severe in people who are infected with HIV. Cook meat until it's well done. Don't use dairy products that aren't treated for bacteria, called pasteurized. Don't eat raw eggs and raw seafood such as oysters, sushi or sashimi. Don't drink water you don't know is safe.
• Get the right vaccinations. These may prevent common infections such as pneumonia, influenza, COVID-19 and mpox. Your healthcare professional also may suggest other vaccinations, including those for HPV, hepatitis A and hepatitis B. Vaccines that don't have live viruses mostly are safe. But most vaccines with live viruses are not safe because of your weakened immune system.
• Take care with pets. Some animals may carry parasites that can cause infections in people who are HIV positive. Cat stool can cause toxoplasmosis, reptiles can carry salmonella, and birds can carry cryptococcus or histoplasmosis. Wash hands thoroughly after handling pets or emptying litter boxes.

People who are infected with HIV sometimes try dietary supplements that claim to boost the immune system or help with side effects of anti- HIV medicines. But there are no studies that show these claims are true. And many supplements can get in the way of other medicines you take.

Always check with your healthcare professional before taking any supplements or alternative therapies to make sure they won't affect the way your medicines work.

Supplements that may be helpful

There's little evidence to show that any supplements for HIV work. Some examples with limited research include:

• Acetyl-L-carnitine. Researchers have used acetyl-L-carnitine to treat nerve pain, numbness or weakness, called neuropathy, in people with diabetes. It may also ease neuropathy linked to HIV for people who don't have enough acetyl-L-carnitine in their bodies.
• Whey protein and certain amino acids. Early evidence suggests that whey protein, a cheese byproduct, can help some people with HIV gain weight. The amino acids L-glutamine, L-arginine and hydroxymethylbutyrate (HMB), also may help with weight gain.
• Probiotics. There is some evidence that the probiotic Saccharomyces boulardii may help with HIV-related diarrhea. Use only as your healthcare professional directs. Bovine colostrum also is being studied for treating diarrhea. But more research is needed.
• Vitamins and minerals. Vitamins A, D, E, C and B and the minerals zinc, iron and selenium may help if you have low levels of them. Talk to your health professional before taking them. Too much of some vitamins and minerals can be harmful.

Supplements that may be dangerous

• St. John's wort. Often used for depression, St. John's wort can reduce how well several types of anti- HIV medicines work by more than half.
• Garlic supplements. Garlic itself may help strengthen the immune system. But garlic supplements can reduce how well some anti- HIV medicines work. Eating some garlic in food seems to be safe.
• Red yeast rice extract. Some people use this to lower cholesterol. Don't take it if you take a protease inhibitor or a statin.

Mind-body practices

Practices such as yoga, meditation and massage have been shown to reduce stress as well as provide relaxation and improve quality of life. While they need more study, these practices may be helpful if you're living with HIV/ AIDS.

Getting a diagnosis of any life-threatening illness can cause distress. The emotional, social and financial effects of HIV/ AIDS can make coping with this illness very hard for you and for those close to you.

But there are many services and resources for people with HIV. Most HIV/ AIDS clinics have social workers, counselors or nurses who can help you or put you in touch with people who can help you.

They may be able to:

• Arrange transportation to and from medical appointments.
• Help with housing and child care.
• Assist with employment and legal issues.
• Provide support during financial crises.

It's important to have a support system. Many people with HIV/ AIDS find that talking with someone who knows about their disease gives them comfort.

If you think you might have an HIV infection, you're likely to start by seeing your family healthcare professional. You may be sent to an infectious disease specialist who focuses on treating HIV/ AIDS.

What you can do

Before your appointment, think about the answers to these questions and take them to your appointment:

• How do you think you were exposed to HIV?
• What are your symptoms?
• Do you have risk factors, such as having sex without protection or shooting illicit drugs?
• What medicines or supplements do you take?

What to expect from your doctor

Your healthcare professional asks you questions about your health and lifestyle and does a physical exam, checking you for:

• Swollen lymph nodes.
• Sores on your skin or in your mouth.
• Problems with your nervous system.
• Unusual sounds in your lungs.
• Swollen organs in your belly.

What you can do in the meantime

If you think you might have an HIV infection, protect yourself and others before your appointment. Don't have sex without using protection. If you shoot illicit drugs, always use a fresh, clean needle. Don't share needles with others.