Medically Reviewed By William C. Lloyd III, MD, FACS

What are HIV and AIDS?

HIV (human immunodeficiency virus) is a virus that attacks the immune system and, left untreated, causes AIDS (acquired immune deficiency syndrome).

AIDS is an irreversible immune system disorder that prevents the body from fighting off other infections. HIV infection is treatable; however, once the infection progresses to AIDS, the condition has no cure.

HIV is most often contracted through sexual contact. The virus can also be passed to another person through contact with blood or body fluids. This can occur through blood transfusions, sharing needles contaminated with HIV, and during pregnancy and breastfeeding.

Early symptoms of HIV resemble flu symptoms, such as fatigue, headache, fever, and swollen glands, which may start 1 to 2 months after infection then disappear. AIDS, which can develop as many as 10 years after HIV infection, is characterized by persistent and more severe symptoms and such conditions as herpes, tuberculosis, pneumonia, encephalitis, certain cancers, and neurologic problems.

More than 700,000 Americans have died with HIV since the U.S. AIDS epidemic began in 1981; millions more have died with the disease worldwide. However, early detection and treatment advances have made HIV a manageable condition. An estimated 1.2 million people in the U.S. are living with HIV—though an estimated 13% are not aware they have HIV.

There is not yet a cure or vaccine for HIV or AIDS, but early HIV diagnosis and treatment can slow the disease. Effective HIV treatment can greatly delay and even prevent AIDS, improve quality of life, and help prevent the spread of HIV.

In some cases, rapid treatment with medication can prevent the development of HIV infection after exposure to the virus. This prophylactic treatment needs to begin within 72 hours after exposure to HIV.

Seek prompt medical care if you think you may have been exposed to HIV and experience symptoms, such as chills, fatigue, fever, mouth sores, muscle aches, night sweats, rash, sore throat, or swollen lymph nodes. Because these symptoms are similar to other conditions, the only way to confirm a diagnosis is through an HIV test.

Seek urgent medical care for symptoms of AIDS, including depression; chronic diarrhea; extreme fatigue; heavy night sweats; lymph node swelling that persists; memory loss; pneumonia; rapid weight loss; recurring fever; or red, brown or purplish lesions on the skin or inside the eyelids, mouth or nose.

What are the stages of HIV and AIDS?

Without treatment, HIV infection progresses in stages:

  • Stage 1, acute HIV infection: People are very contagious at this stage, when there are large amounts of virus in the bloodstream. Some people develop flu-like symptoms within 2 to 4 weeks after infection.
  • Stage 2, clinical latency or HIV dormancy: The virus is still replicating, but at very low levels compared to stage 1. Without treatment, stage 2 can last a decade or longer. With treatment, stage 2 can last for several decades or be lifelong.
  • Stage 3, AIDS (acquired immune deficiency syndrome): HIV has damaged the immune system to such a degree it can no longer protect the body from infection and disease. Stage 3 survival is about three years. People with AIDS may have a high viral load and are very infectious.

What are the symptoms of HIV and AIDS?

The symptoms of an HIV infection result from the virus attacking the cells of the body’s immune system. Early in the disease, many people with HIV infection have no symptoms. Some people may experience flu-like symptoms that occur about 2 to 4 weeks after infection, but it can take longer to develop symptoms.

Symptoms of HIV infection

Early symptoms of HIV can include:

  • Fatigue

  • Headache

  • Recurring fever

  • Swollen glands

  • Weight loss

  • Yeast infections

Symptoms of AIDS

Mild, early-stage symptoms of HIV infection generally go away within several weeks after exposure to the virus. There may be no symptoms as many as 10 years or longer after HIV infection.

Over this time, HIV gradually destroys the helper T cells of the immune system. This leads to a weakening of the body’s immune system, leading to AIDS.

Symptoms of stage 3 HIV (AIDS) include:

  • Chronic diarrhea (lasting more than a week)

  • Depression

  • Extreme fatigue and tiredness

  • Frequent yeast infections (including oral thrush, a yeast infection in the mouth)

  • Heavy and frequent night sweats

  • Lymph node swelling that persists (longer than three months)

  • Memory loss and other neurologic conditions

  • Pelvic inflammatory disease that resists treatment

  • Pneumonia

  • Rapid weight loss

  • Skin lesions

  • Skin rashes

  • Tuberculosis

Serious late-stage complications of AIDS

In the later stages of AIDS, the immune system can no longer fight off infections, making the body vulnerable to opportunistic infections (infections related to being immunocompromised) that can become serious or fatal.

Complications of advanced AIDS include:

  • Certain cancers, such as Kaposi’s sarcoma

  • Dehydration and electrolyte imbalance due to long-term diarrhea

  • Dementia

  • Depression

  • Encephalitis

  • Hepatitis

  • Herpes

  • Memory loss and confusion

  • Pneumonia

  • Serious opportunistic infections, such as tuberculosis, cytomegalovirus, meningitis, yeast infections, and toxoplasmosis

  • Shingles

  • Wasting syndrome

What causes HIV and AIDS?

HIV and AIDS are caused by infection with the human immunodeficiency virus (HIV).

Human immunodeficiency virus infects and reproduces in specific immune cells—mainly T-cells bearing the CD4 receptor on their surface. HIV disables and depletes CD4 cells from the immune system, which makes it hard for the body to fight off infections and some forms of cancer. As the immune system deteriorates with time, complications begin to surface, leading to AIDS.

A person’s genetic makeup can also play a role in HIV and AIDS. Scientists have discovered certain variations in HLA genes and other genes that affect a person’s susceptibility or resistance to HIV. Genetic research has even led to a new class of anti-HIV drugs.

How HIV is transmitted

HIV is passed to another person through contact with blood or bodily fluids. Infected blood, semen, pre-seminal fluid, rectal fluid, vaginal fluid, and breast milk can transmit the virus to mucous membranes or broken tissue upon direct contact. (The mouth, vagina, rectum and penis have mucous membranes.)

HIV can also be passed to a newborn during pregnancy, childbirth or while breastfeeding, though this is rare. It is extremely rare for HIV to spread via oral sex or contact with infected blood from broken skin or wounds.

Contracting HIV through transfusions of blood products also has become very rare since 1985 because donated blood products are now tested for HIV.

HIV is NOT spread by biting insects, sweat, saliva, or sharing food, drinks or toilets.

What are the risk factors for HIV and AIDS?

A number of factors are linked to an increased risk of contracting HIV, including:

  • Being born to or breastfed by a birthing parent with HIV or AIDS

  • Having had a transfusion of blood products before 1985

  • Having another type of sexually transmitted disease, such as chlamydia, genital herpes, HPV, or gonorrhea

  • Having certain infectious diseases, such as tuberculosis and hepatitis

  • Having sex, including vaginal, oral, or anal sex, without a condom or other barrier method. There is an increased risk for people with multiple sex partners who do not use a barrier method.

  • Sharing contaminated needles, such as to inject drugs or for tattooing

Reducing your risk of HIV infection

Not all people who are at risk for HIV infection will develop the disease. You may be able to lower your risk of contracting HIV by:

  • Abstaining from sexual activity

  • Engaging in sexual activity within a mutually monogamous relationship in which neither partner is infected with HIV or has risk factors for the infection. If having sex with multiple partners, be aware of a potential partner’s HIV status and use a barrier method, such as condoms, to reduce the risk of infection.

  • Getting regular, routine medical care and prenatal care

  • Not sharing needles with others

  • Seeking medical care promptly after possible exposure to HIV or after sexual activity without a condom or other barrier method. Some medications can reduce the risk of HIV infection before or soon after exposure to the HIV virus.

  • Using latex condoms or other barrier methods properly

What are the diet and nutrition tips for HIV and AIDS?

Nutrition is an essential component of an HIV or AIDS treatment plan. While there is no diet that can specifically improve your immune system, eating nutritious foods contributes to your overall health, including your immunity, and allows you to better manage HIV symptoms and treatment side effects.

Maintaining a healthy weight is often a challenge for people living with HIV. Many people experience weight loss and may become underweight. This increases the risk of infections and other complications.

Additionally, some HIV symptoms make eating more difficult. Nausea can lead to loss of appetite, and fatigue can make it harder to prepare healthy meals. Some people experience mouth sores or find that food doesn't taste as good as it used to.

Your healthcare team can provide guidance on diet and nutrition as you follow your treatment plan. You may be able to work with a registered dietitian to develop meal strategies that help you maintain proper nutrition, manage side effects, and eat foods you enjoy.

Steps to increase calorie intake with HIV

General steps you can take to increase your calorie intake and prevent weight loss include:

  • Adding carbohydrates, including moderate amounts of breads, fruits (fresh or dried), honey, oatmeal, pasta, potatoes, and rice

  • Getting more protein, such as lean meats, fish, nut butters, beans, eggs and cheese

  • Increasing fats, including moderate amounts of avocados, butter, cream cheese, olives, and peanut butter

Tips to improve appetite with HIV

The symptoms of HIV and side effects from treatment can decrease appetite and make mealtimes a challenge. To prevent weight loss and maintain steady eating habits, try these tips:

  • Avoid foods or drinks that make you feel bloated or gassy, such as carbonated water or soda, beans, broccoli, Brussels sprouts, cabbage, cauliflower, and onions.

  • Create a pleasant space for meals that you enjoy being in. When possible, eat with family or friends to make the experience more social.

  • Drink less as you get closer to mealtime. Drinking too much right before you eat can make you feel less hungry.

  • Eat a series of small meals or snacks throughout the day, rather than three big meals. This can make eating more manageable and keep your blood sugar steady.

  • Exercise, even if it’s light activity. This can help stimulate your appetite.

  • Focus on your favorite foods if that’s what will motivate you to eat.

  • If having difficulty swallowing, opt for soft foods, such as bananas, mashed potatoes, oatmeal, and yogurt. Also avoid acidic or spicy foods, and eat foods cold or at room temperature.

  • Manage nausea by avoiding foods with strong flavors or smells. Drinking tea with ginger root or sucking on ginger candy can also help reduce nausea.

  • Take advantage of times when your appetite is good and eat anytime you feel the desire to. 

Tips to stay hydrated with HIV

Symptoms such as diarrhea and vomiting can result in dehydration. This makes staying hydrated particularly important when living with HIV.

Having enough fluids helps your body absorb nutrients and maintain the energy you need. Proper hydration can also help manage side effects, such as dry mouth and constipation.

You can prevent dehydration by:

  • Avoiding alcohol

  • Avoiding drinks with caffeine, such as cocoa, coffee, sodas and tea

  • Drinking non-caffeinated liquids, such as decaf coffee, decaffeinated tea, fruit-infused waters, or fruit juices mixed with water

  • Reducing intake of salty foods, including packaged snacks and fried foods

  • Starting and ending each day by drinking a glass of water

  • Sucking on frozen liquids, such as ice cubes, flavored ice pops, or frozen fruit bars

Food safety with HIV

Taking steps to ensure food safety is always important, but even more so when living with HIV. Because the virus weakens your immune system, you are less able to fight off infections, including food-borne illnesses.

Tips for safely handling, preparing, and consuming food include:

  • Avoiding consumption of raw or undercooked foods, including soft-boiled eggs, sushi, and salad dressings or pasta sauces (i.e. carbonara) that may contain raw egg

  • Checking expiration dates on packaged foods 

  • Keeping counters, cutting boards, plates and utensils clean

  • Measuring the internal temperature of cooked meats to ensure they reach a minimum of 165°F

  • Rinsing fruits and vegetables before eating

  • Thawing frozen foods in the refrigerator or microwave, never at room temperature

  • Washing hands thoroughly before preparing and eating food, as well as after meals

Depending on your level of nutrition, your care team may recommend taking a vitamin or other nutritional supplement. Always talk with your doctor before starting any supplement, as some specific minerals or vitamins can interact with your medications. And remember that supplements are never intended to replace the benefits of eating a healthy and nutrition diet.

How do doctors diagnose HIV and AIDS?

A healthcare professional will diagnose HIV infection with tests that detect viral antigens or viral antibodies, or both, in a sample of blood or oral fluid. Most diagnostic and screening HIV tests are combined antigen/antibody tests. Home testing and rapid-result kits are typically antibody tests. A clinic needs to confirm rapid and home test results.

Another test—the nucleic acid test (NAT), or HIV viral load test—directly measures the amount of HIV in a blood sample. It is useful when measuring the effect of treatment and when a person is highly likely to be infected with HIV and yet antigen/antibody tests are negative.

HIV may not be detectable in the first 1 to 3 months after infection, and a series of tests may be needed to diagnose or rule out HIV infection.

People who are HIV-positive receive an AIDS diagnosis if they develop an increasing number of so-called opportunistic infections. These illnesses are more common in people with suppressed immune systems, including HIV patients, because the immune system can no longer fight off disease.

A CD4 cell count of less than 200 cells/mm3 also indicates HIV has turned into AIDS. The CD4 cell count of a healthy person who does not have HIV is 500 to 1500 cells/mm3.

Your doctor or healthcare professional will discuss your individual diagnosis with you and together you can develop next steps to treat and manage the disease.

What are the treatments for HIV and AIDS?

Treatment of HIV starts with seeking regular medical care. This allows your healthcare professional to best evaluate your symptoms and risks and provide regular testing for HIV infection as appropriate. Regular medical care can increase your chances of catching and treating HIV in its earliest stages before serious complications occur.

Medication is the only way to treat HIV infection and delay or prevent AIDS. Since HIV is a retrovirus, medications that inhibit HIV are known as antiretroviral drugs.

Antiretroviral medications for HIV 

Antiretroviral therapy (ART) is a combination of antiretroviral drugs that blocks HIV from producing more virus, which reduces viral load and prevents or delays AIDS. ART also reduces the risk of spreading the virus.

A person with HIV must take these medications daily and cannot skip doses. Over time, the potency of one drug may decline and the doctor may substitute other drugs.

Antiretroviral medications include:

  • Entry inhibitors

  • Fusion inhibitors

  • Integrase inhibitors

  • Protease inhibitor

  • Reverse transcriptase inhibitors

Preventive treatment for HIV 

Some medications are available that can reduce the risk of HIV infection before or soon after exposure to the HIV virus. These include:

  • PrEP (pre-exposure prophylaxis): Two antiretroviral drugs in a pill (brand name Truvada) taken daily by people at high risk for contracting HIV. When combined with barrier methods, such as condoms, PrEP greatly reduces the risk of HIV infection.

  • PEP (post-exposure prophylaxis): An emergency dose of antiretrovirals taken within 72 hours after potential or known HIV exposure, such as through sharing needles or sex without a condom or other barrier method. One of the drugs can cause birth defects, so doctors prescribe other drugs to people early in pregnancy and who have the potential to become pregnant.

How do HIV and AIDS affect quality of life?

An HIV diagnosis is life-changing, but today HIV is often a manageable condition, and people who are HIV-positive can live long, healthy lives.

However, living with HIV still presents challenges, either from symptoms of HIV itself or side effects from HIV treatments. Experts measure these factors as health-related quality of life (HRQoL).

Overall, issues that lower a patient’s HRQoL include:

  • HIV symptoms

  • Progression to AIDS

  • Treatment side effects and difficulty with medication regimen

  • Lack of social support

  • Experiencing anti-HIV/AIDS stigma

  • Low energy level, fatigue

  • Poor coping skills

  • Presence of mental health disorder

  • Memory and thinking problems

Factors that raise HRQoL include:

  • Employment and higher income and education level

  • Younger age

  • Stable relationships and good social support

  • Treatment success (with manageable side effects)

  • Good communication with healthcare providers

Living well with HIV is truly a team effort. Your care team can answer questions and help you navigate your treatment plan to manage symptoms and side effects.

Spending time with supportive friends and family members can provide emotional strength, as well as caregiving assistance when needed.

Finally, HIV/AIDS support groups, both online and in-person, can connect you with a community of other people living with HIV or AIDS to share your experiences and face each day’s challenges together.

What are the potential complications of HIV and AIDS?

As HIV progresses to AIDS, complications from the condition become life-threatening. Successful HIV treatment can prevent or delay the onset of AIDS, but when a person does develop AIDS, serious complications include:

  • Cardiovascular disease

  • Certain cancers, such as Kaposi’s sarcoma and lymphoma

  • Dehydration and electrolyte imbalance due to long-term diarrhea

  • Dementia

  • Depression

  • Loss of vision due to retinal CMV infection or other ocular opportunistic infections

  • Metabolic syndrome (associated with use of protease inhibitors)

  • Neurological problems, such as memory loss, confusion, and encephalitis

  • Pneumocystis carinii pneumonia

  • Serious opportunistic infections, such as tuberculosis, cytomegalovirus, meningitis, yeast infections, and toxoplasmosis

  • Wasting syndrome

What is the survival rate and prognosis for HIV and AIDS?

Prognosis and life expectancy with HIV depends on many different factors, but the outcome is generally very good with early diagnosis and effective treatment. A 10-year study from the United Kingdom showed that patients who had a good response to modern HIV therapies had a normal, if not better, life expectancy than average.

Annually, for the past five years, approximately 13,000 to 16,000 people in the U.S. with diagnosed HIV or AIDS have died, due to any cause. (This means if someone who was HIV-positive died from an unrelated condition or event, it was still listed as an HIV death.) Contrast this data to the early 1990s, when more than 50,000 Americans a year died with the disease. Deaths with HIV have declined sharply since the mid-1990s with the introduction of anti-HIV therapies.

Unfortunately, left untreated, the progression to AIDS has a very poor prognosis, with a survival rate of 10%.

These statistics underscore the need for HIV awareness and testing, to allow for early detection and successful treatment of HIV infection.

HIV and AIDS awareness

HIV remains a significant public health problem in the United States and globally. Many U.S. efforts to reduce the spread of HIV focus on sexual health awareness and HIV testing and prevention—particularly among adolescents and young adults. Learn more at the Trusted Source Centers for Disease Control and Prevention (CDC) Governmental authority Go to source National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention Trusted Source Centers for Disease Control and Prevention (CDC) Governmental authority Go to source .

December is HIV/AIDS awareness month, marked by a red ribbon. World AIDS Day is December 1.

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  1. An P, Winkler CA. Host genes associated with HIV/AIDS: advances in gene discovery. Trends Genet. 2010;26(3):119–131. 
  2. O’Brien SJ, Nelson GW. Human genes that limit AIDS. Nat Genet 2004;36(6):565-574. 
  3. Cummins NW, Badley AD. Making sense of how HIV kills infected CD4 T cells: implications for HIV cure. Mol Cell Ther. 2014;2:20. 
  4. Centers for Disease Control and Prevention. HIV Surveillance Report, 2017; vol. 29. Published November 2018.
  5. HIV/AIDS. Centers for Disease Control and Prevention. 
  6. Today’s HIV/AIDS Epidemic (2016). Centers for Disease Control and Prevention. 
  7. May MT, Gompels, M, Delpech, V, et al. Impact on life expectancy of HIV-1 positive individuals of CD4+ cell count and viral load response to antiretroviral therapy. AIDS. 2014;28(8):1193-202. 
  8. Duracinsky M, Herrmann S, Berzins B, et al. The development of PROQOL-HIV: an international instrument to assess the health-related quality of life of persons living with HIV/AIDS. J Acquir Immune Defic Syndr. 2012;59(5):498-505. 
  9. Miners A, Phillips A, Kreif N, et al. Health-related quality-of-life of people with HIV in the era of combination antiretroviral treatment: a cross-sectional comparison with the general population. Lancet HIV. 2014;1(1):e32-40. 
  10. Degroote S, Vogelaers D, Vandijck DM. What determines health-related quality of life among people living with HIV: an updated review of the literature. Arch Public Health. 2014;72(1):40.
  11. Bope ET, Kellerman RD (Eds.) Conn’s Current Therapy. Philadelphia: Saunders, 2013.
  12. Cohen MS, Hellmann N, Levy JA, et al. The spread, treatment, and prevention of HIV-1: evolution of a global pandemic. J Clin Invest 2008; 118:1244.
  13. Sterne JA, Hernán MA, Ledergerber B, et al. Long-term effectiveness of potent antiretroviral therapy in preventing AIDS and death: a prospective cohort study. Lancet 2005; 366:378.
  14. Diet and Nutrition and HIV. U.S. Department of Veterans Affairs.
  15. Nutrition Tips to Keep the Immune System Strong for People with HIV-AIDS. Academy of Nutrition and Dietetics.
  16. HIV and AIDS. Johns Hopkins Medicine.
  17. Symptoms of HIV. U.S. Department of Health & Human Services.
  18. Global HIV & AIDS statistics — Fact sheet. UNAIDS.
Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2021 Nov 7
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