HIV is a virus that affects the immune system, which helps your body fight infections and stay healthy. It does this by attacking CD4 cells, a type of white blood cell. Over time, if HIV is not treated, it reduces these cells and makes it harder for your body to fight off infections. The good news is that HIV is both preventable and treatable.

HIV can be present in the body without any noticeable symptoms for a long time, which contributes to many people not knowing they have it. This is why getting tested regularly and knowing your status is a powerful way to keep yourself and your community safe.

Sources: aidsmap — HIV-1 and HIV-2, Stanford Health Care — HIV/AIDS

Acquired Immune Deficiency Syndrome (AIDS) is the most advanced stage of HIV. AIDS develops when HIV has significantly weakened the immune system.

This is measured by either a very low CD4 cell count or by the presence of opportunistic infections — illnesses that occur more easily when the immune system is weakened, such as certain types of pneumonia or some cancers.

Today, most people living with HIV will not develop AIDS. With early diagnosis and consistent treatment, HIV can be managed and prevented before it reaches this stage and people living with HIV can live long, full lives.

Sources: Stanford Health Care — HIV/AIDS

Viral load refers to the amount of HIV in the blood. It is measured through a blood test and helps show how active the virus is in the body, as well as its continued effects on the body, especially the immune system.

In the early stages of HIV, viral load is high because the virus multiplies quickly. Over time and with treatment, it will likely decrease and stabilize, often reaching a level of “undetectable,” meaning the level of virus is too low to be measured by standard tests. However, without treatment, viral load can increase as the immune system becomes more affected.

HIV progresses in stages. Without treatment, it can move through these stages over time. However, with treatment, progression of the disease can be significantly slowed or prevented entirely.

Acute HIV (initial infection):

This is the earliest stage of HIV, typically occurring 2 to 4 weeks after infection. During this time, the virus multiplies and spreads, and the viral load is high, which means that the virus can more easily be passed to others. Some people may experience severe to mild flu-like symptoms during this period.

Chronic HIV:

This stage occurs between early HIV and advanced HIV (AIDS). HIV is still active in the body but progresses more slowly than the initial infection. Many people with chronic HIV may have mild or no HIV-related symptoms. During this stage, the viral load decreases from the initial infection and settles at a lower level.

Without treatment, HIV will continue to infect and destroy the CD4 cells that help the body recognize and fight infections, even in people with no symptoms. As the number of CD4 cells decreases, the immune system becomes less able to respond effectively to infections. As a result, infections may occur more often, last longer, or be harder to recover from and symptoms may begin to appear or become more severe.

Fortunately, there are a variety of effective treatment options available today. With proper treatment, people living with HIV can have long and healthy lives.

Advanced HIV or AIDS:

This is the most advanced stage of HIV, which occurs when HIV has reduced the number of CD4 cells to levels low enough that the immune system is no longer able to function properly.

At this stage, the immune system can no longer control certain infections. Such infections may require more intensive or ongoing medical care, and can affect different parts of the body, including the lungs, brain, or digestive system.

Advanced HIV is identified by either very low CD4 levels or the presence of specific serious conditions, including certain infections and cancers associated with a weakened immune system.

This stage reflects a level of immune system damage that has already occurred, rather than changes that are still developing over time. This stage can be prevented with early diagnosis and consistent treatment.

Sources: Clinicalinfo.HIV.gov — Glossary (PDF), Clinicalinfo.HIV.gov — Acute HIV infection, aidsmap — Stages of HIV infection

HIV symptoms can vary from person to person. Especially during the beginning stages of HIV, many people have mild symptoms or no symptoms at all. This is why it’s crucial that people get tested regularly.

Early (acute) HIV:

In the early stage of HIV, many people have flu-like symptoms. Symptoms at this stage can vary widely. Some people have mild symptoms or none at all, while others may need medical care for more severe symptoms.

Common symptoms include:

• Sore throat
• Fever
• Headache
• Fatigue
• Night sweats
• Mouth sores
• Skin rash
• Muscle aches
• Swollen lymph nodes

Some people may also experience changes related to reproductive or sexual health such as:

• Changes in menstrual cycle
• Vaginal yeast infections
• Pelvic pain
• Pain during sex

Chronic HIV:

During this stage, many people do not have noticeable symptoms. HIV is still active in the body but symptoms may be mild or not present.

When symptoms do occur, they can include:

• Ongoing fatigue
• Swollen lymph nodes
• Low-grade fever
• Occasional night sweats
• Mild weight changes

These symptoms can be easy to overlook and may be caused by many different conditions. Even without symptoms, HIV continues to affect the body.

Advanced HIV or AIDS:

If HIV is not treated, the immune system becomes weakened. Symptoms may include:

• Ongoing or severe infections
• Unexplained weight loss
• Extreme fatigue
• Persistent fever or night sweats

These symptoms are not specific to HIV/AIDS and can be caused by many different conditions. It’s important to talk with a doctor to confirm your HIV status.

Sources: aidsmap — Stages of HIV infection, HIVcare.org — HIV basics

HIV/AIDS is transmitted when certain bodily fluids come in contact with a mucous membrane (such as the vagina or rectum), through damaged tissue (like a cut or tear), or are injected into the bloodstream (such as from a needle or syringe). These fluids include:

• Blood
• Vaginal fluids
• Rectal fluids
• Breast milk
• Semen (cum)
• Pre-seminal fluid (pre-cum)

HIV/AIDS can be transmitted through:

• Sex without a barrier method (condom, internal condom, or dental dam): Includes vaginal, anal, or oral sex where semen, pre-seminal fluid, vaginal fluids, or rectal fluids can enter the body. HIV/AIDS is most easily transmitted through anal and vaginal sex. The risk from oral sex is lower but HIV/AIDS can still be passed, especially if fluids enter the mouth or there are cuts, sores, or bleeding gums. HIV/AIDS cannot be transmitted through sex when a person living with HIV is on treatment and has an undetectable viral load (U=U).
• Sharing needles or injection equipment when injecting drugs: This includes needles, syringes, cookers, cotton, or water that may have blood on them. HIV/AIDS can be passed through blood left on equipment used, even in small amounts.
• Parent to child during pregnancy, birth, and breastfeeding: HIV/AIDS can be passed during these stages, but treatment greatly reduces risk.
• Non-sterile medical or cosmetic procedures: HIV/AIDS can be transmitted if needles or equipment are reused or not properly sterilized during procedures like injections, tattoos, or piercings.
• Needlestick or sharp injuries: This can happen when a needle or sharp object punctures the skin and exposes someone to blood, often in healthcare or workplace settings.
• Blood transfusions or organ transplants: Blood and organs are routinely screened in the United States, making this extremely rare.

Sources: Stanford Health Care — Risk of exposure

HIV/AIDS is not spread through everyday contact. It is not transmitted through:

• Sweat, tears, or saliva
• Hugging, kissing, or touching
• Coughing or sneezing
• Sharing food, drinks, utensils, bedding, and towels
• Using public or shared facilities such as bathrooms, swimming pools, or drinking fountains
• Toilet seats
• Insect bites (such as mosquitoes or spiders)

HIV/AIDS also cannot be transmitted through sex when a person living with HIV is on treatment and has an undetectable viral load (U=U).

Certain communities are disproportionately impacted by HIV. In the United States, this includes Black and Latino gay and bisexual men and men who have sex with men (MSM), transgender individuals, and those who use unsterile or unsanitary needles and/or syringes.

For example, the Centers for Disease Control (CDC) has projected that, at recent diagnosis rates, about 1 in 2 Black MSM and 1 in 4 Latino MSM would be diagnosed with HIV within their lifetime. Transgender people are also disproportionately represented in new HIV diagnoses. Among people who use injection drugs, about 1 in 8 are diagnosed with HIV globally.

People in these communities face certain challenges outside of their control that affect their ability to access and understand testing and treatment, as well as get the care they need after a positive HIV diagnosis.

Sources: CDC — Gay & bisexual men, HIV.gov — Lifetime diagnosis projections, HIV.gov — Substance use & HIV risk, CDC — Transgender people, HIV.gov — Statistics, NIH PMC8672311, NIH PMC12407415

Discrimination, marginalization, shame, and stigma can make it harder to get tested, use prevention like PrEP, or stay on treatment. When access to these services is limited or inconsistent, HIV is more likely to go undiagnosed for longer periods and overall rates remain high.

For example, many transgender people face economic and healthcare barriers that limit access to care. About 29% of transgender people live in poverty, which can make it difficult to afford healthcare, transportation, and taking time off for doctor’s appointments. Many transgender people also do not have health insurance, limiting access to regular testing, prevention, and treatment.

Transgender people of color also face intersecting forms of discrimination, such as racism and transphobia. These experiences can create additional barriers and disrupt consistent, affirming care.

Sources: HRC — Understanding the transgender community, CAP — LGBTQI+ underinsurance & discrimination

There are real-world challenges that can make it harder to successfully manage HIV care. These barriers are shaped by the conditions people live in, and common barriers to care include:

• Not having health insurance or being unable to afford care
• Difficulty taking time off work or finding childcare
• Avoiding care due to past experience(s) of discrimination
• Lack of culturally-competent or affirming providers
• Language barriers or not having access to interpretation services
• Lack of reliable transportation
• Unstable housing or frequent moves that make it harder to stay connected to care
• Immigration-related concerns including fear of ICE or immigration enforcement when accessing clinics, hospitals, or public programs

Sources: AJPH, amfAR — Barriers to HIV care, Harvard Medical School — LGBTQ health disparities, HRC — Understanding the transgender community

Everyone deserves access to care that is easy to navigate and responsive to their needs.

Affirming HIV care can include:

• Being treated with dignity and respect
• Providers using the correct name and pronouns
• Care that is inclusive of different bodies, identities, and types of sex
• Clear and medically accurate information on HIV prevention and treatment
• Providers who are knowledgeable about LGBT+ health issues

When care is equitable and affirming, people are more likely to access and stay connected to care over time.