The human immunodeficiency virus (HIV) is a virus that attacks the immune system. If left untreated, HIV can progress within a few years and lead to acquired immune deficiency syndrome (AIDS), a set of symptoms and infections that eventually cause death.

Although HIV is not yet curable, it’s very treatable. Following your treatment plan and leading a healthy lifestyle enables most people with HIV to have a typical lifespan.

What Is HIV?

HIV is a retrovirus, which means it stores its genetic material in a special way and copies itself inside the body’s cells. It mainly attacks a certain type of white blood cell called a CD4 cell, also known as a T-helper cell. These send signals to other immune cells, telling them to start fighting off infections.

When HIV infects a CD4 cell, it takes over the cell’s process of making copies. Instead of helping the immune system, the infected cell starts making more copies of the virus. These copies are released into the body to infect more CD4 cells. HIV also destroys CD4 cells, weakening the immune system and leaving the body unable to rally an effective response to cancers and infections.

What Type of Infection Is Human Immunodeficiency Virus?

HIV is a viral infection, which means it comes from a virus similar to the common cold. However, it doesn’t spread as easily as cold and flu viruses.

How Does HIV Spread?

The spread of HIV happens after certain types of contact with different bodily fluids like infected blood, semen, preseminal fluid, vaginal secretions, and rectal fluid. The virus can also be transmitted to a child during childbirth or pregnancy or through breastfeeding and breast milk. In order to infect someone, the infected fluid must come into contact with their bloodstream, a mucous membrane, or an open wound. HIV cannot be spread through saliva.

HIV is most commonly passed through unprotected anal or vaginal sex without condoms or through shared use of needles or other injection equipment. However, it is important to clarify that the virus isn’t transmitted through casual or everyday contact, such as through sharing drinks, hugging, shaking hands, or kissing.

The History of HIV/AIDS

Researchers now know that HIV originated in Kinshasa, in what is today the Democratic Republic of Congo, in 1920, when the virus crossed species from chimpanzees to humans. The first cases were presented to the Centers for Disease Control and Prevention (CDC) in 1981. Five previously healthy gay men in Los Angeles had acquired a rare lung infection called Pneumocystis carinii pneumonia and other infections. The CDC began to receive more reports of severe immune deficiency among gay men. By the end of 1981, there were 337 reported cases of the mysterious disease and 130 deaths.

It would take a few years to piece together that HIV infection leads to AIDS, and several more years to undo the myth that HIV could only affect gay men.

Stigma Surrounding HIV/AIDS Starts To Rise

The media began to raise an alarm that AIDS affected gay men. Some researchers dubbed the condition “gay-related immune deficiency” or “GRID,” furthering and worsening the stigma. Cities like San Francisco and New York began campaigns to close bathhouses and private sex clubs. The U.S. imposed a travel ban to stop immigrants with AIDS from entering the United States.

HIV Begins Spreading Through Blood Donations

In 1982, a nonprofit called the World Federation of Hemophilia presented evidence to the CDC and blood-banking companies that AIDS might be spread through blood transfusions, making it a blood-borne disease. At that time, many still wrongly believed that AIDS only affected homosexual males and wasn’t an infectious disease. Screening for HIV wouldn’t begin at blood banks until 1985.

HIV Awareness Grows and Early Treatments Emerge

In 1986, the International Committee on the Taxonomy of Viruses officially designated the virus that causes AIDS as “human immunodeficiency virus.” Scientists realized that AIDS is the final stage of the infection, developing later as the immune system becomes weak.

The U.S. Food and Drug Administration (FDA) approved the first antiretroviral therapy (ART), zidovudine, as treatment for HIV in March 1987. Antiretroviral drugs could prevent people with HIV from developing AIDS and stop the spread.

The stigma of HIV was slow to improve. In 1990, the U.S. enacted the Americans with Disabilities Act (ADA), which prohibited discrimination against people with disabilities, including those with HIV. It wasn’t until 2010 that the travel ban barring HIV-positive people from entering the U.S. was lifted.

AIDS-Related Deaths Drop as Treatments Improve

The FDA approved the first protease inhibitor, saquinavir, in 1995, and it proved to be an effective treatment for HIV. The new class of ART drugs is credited with an immediate decline of 60 percent and 80 percent in AIDS-related death and hospitalization rates in countries with access to HIV treatment.

In July 2012, the FDA approved a preexposure prophylaxis (PrEP) medication regimen to prevent HIV-negative people with a high risk of HIV transmission from becoming infected. PrEP can reduce the risk of sexual transmission of HIV by more than 99 percent.

By 2017, more than half of the global population with HIV — over 19.5 million people — was receiving antiretroviral treatment. Global HIV advocacy organizations started to promote the slogan “Undetectable = Untransmittable” (“U=U”). This antistigma campaign is based on scientific evidence that people with HIV who achieve an undetectable viral load while on treatment cannot pass the virus to others.

Long-acting injectable medications to prevent HIV have been available since 2021. As opposed to taking a daily pill, you get an injection once every two months. More injectable HIV prevention medications are currently under review but show promise in clinical trials.

How Common Is HIV?

As of 2023, an estimated 1.2 million people ages 13 and up in the U.S. are living with HIV — and about 13 percent of them don’t know they have the virus.

Gay men, bisexual men, and other men who have sex with men are the most affected by HIV. Of the 30,635 new HIV diagnoses in the U.S. in 2020, 68 percent were among gay and bisexual men. Transgender women who have sex with men are also among the groups at highest risk for HIV infection.

People in their 20s and 30s are more likely to be diagnosed with HIV than those in other age groups.

According to HIV.gov, in the U.S., African Americans and Hispanics/Latinos are more affected by HIV than other racial and ethnic groups.

How Is HIV Diagnosed?

The U.S. Preventive Services Task Force (USPSTF) recommends that everyone between the ages of 15 and 65 — as well as all pregnant people — get tested for HIV at least once.

Healthcare providers can detect HIV with blood tests or tests using oral fluids (similar to saliva). Home HIV tests are also available. After someone takes an HIV test, the results can show whether they have the virus. If the result is positive, doctors may do more tests — such as checking a person’s CD4 count — to see how the virus is affecting their immune system and look for other infections that might happen with HIV.

It’s important to know that there is a window period, which is the time between when someone gets HIV and when a test can actually detect it. During this time, a person can still spread the virus even if their test result isn’t positive yet.

Rapid HIV tests and self-testing kits continue to become more accurate and accessible, which helps people diagnose HIV earlier.

What Are the Symptoms of HIV?

HIV symptoms vary by the stage of HIV infection. An estimated 10 percent to 60 percent of individuals with early HIV infection will not experience symptoms. In the other cases, a person may experience flu-like symptoms — known as the acute retroviral syndrome — within one or two months after becoming infected. Symptoms generally last a few weeks and can include fever, sore throat, rash, diarrhea, weight loss, and headache.

During the chronic or latent stage — which lasts approximately eight to 10 years without treatment — a person may experience swollen lymph nodes or no symptoms at all. By sticking to their recommended treatment regimen, most people with HIV will never experience progression of the disease. Without treatment, HIV causes symptoms like frequent infections, fever, fatigue, sweats, diarrhea, and weight loss.

In the final stage of HIV, known as AIDS, a person has a severely compromised immune system, leading to severe infections and cancers that eventually cause death.

How Is HIV Treated?

HIV is treated with antiretroviral therapy. There are many different classes of ART medications, and most people are treated with a combination of drugs. Certain types of preventive ART can also protect against transmission. Infections that develop as a complication of HIV may be treated with antibiotics, antifungals, and other classes of antiviral medications.

The long-acting injectable cabotegravir is a version of PrEP that makes it easier to manage HIV. Instead of taking it daily, you inject it once every two months. New classes of medications use different mechanisms to treat HIV, which helps people overcome medication resistance (medications becoming less effective the longer you take them).

Is There a Cure for HIV or AIDS?

There is no cure for HIV or AIDS. However, treatments for HIV are so effective that they prevent AIDS from developing in nearly every case. Treatments can also effectively lower the risk of transmitting HIV between sexual partners.

Talk With Others Who Understand

On myHIVteam, the social network for people with HIV and their loved ones, members come together to ask questions, give advice, and share their stories with others who understand life with HIV.

What questions do you have about HIV/AIDS? Do you want to know your HIV status? Share your insights in the comments below, or start a conversation by posting on your Activities page.