HIV Basics

HIV, or human immunodeficiency virus, is a virus that attacks a key part of the immune system, called T-cells or CD4 cells, which help defend the body against illness. Left untreated, HIV can destroy so many CD4 cells that the body has difficulty fighting infections and diseases. When that happens, HIV can lead to an AIDS diagnosis.

The only way to know if you have HIV is to get tested. These tests look for antibodies in the blood or saliva that the immune system makes in response to HIV. Some HIV tests also look for pieces of the virus called antigens.

There is no cure for HIV, however, there are highly effective prescription medications, called antiretrovirals (ARVs), that work to reduce the amount of HIV in the body (viral load) to a very low, even undetectable, level. This keeps the immune system working and prevents illness. When HIV is undetectable, it also cannot be transmitted to sexual partners.

Click here for more about HIV treatment.

AIDS, or acquired immunodeficiency syndrome, is a diagnosis made by a healthcare provider that indicates an advanced stage of HIV.

An AIDS diagnosis is made when the number of healthy immune system cells (also known as one’s CD4 or T-cell count) drops to a low level or when someone with HIV develops certain illnesses, called opportunistic infections, which result from a weakened immune system. These may include Kaposi’s sarcoma, tuberculosis, lymphoma, pneumonia and other cancers such as invasive cervical cancer.

With ongoing medical care and treatment, HIV can be controlled and prevented from advancing to AIDS. Clinical guidelines recommend that antiretroviral (ARV) treatment as soon as possible after diagnosis.

CDC, Sources and Definitions: Acquired Immunodeficiency Syndrome (AIDS). June 2023.
NIH, Guidelines for the Use of Antiretroviral Agents in HIV-1-Infected Adults and Adolescents: Initiation of Antiretroviral Therapy. March 2018.
CDC, Treating HIV. April 2024. 

The most common way to get HIV is through unprotected anal or vaginal sex with someone who is unaware they have HIV or who does not have their HIV controlled with antiretroviral (ARV) treatment.

Sharing needles, syringes or other injection-drug equipment with someone with HIV can also result in infection.

HIV can be passed during pregnancy, birth or through breastfeeding. Ongoing ARV treatment to achieve and maintain viral suppression both during pregnancy and postpartum substantially reduces the risk of perinatal transmission to less than 1%, but not zero. The U.S. Centers for Disease Control and Prevention (CDC) recommends that pregnant people living with HIV who have questions about breastfeeding or who want to breastfeed should receive patient-centered, evidence-based counseling on their infant feeding options.

HIV is not spread through casual contact, such as hugging or shaking hands. It also cannot be transmitted through the air or by sharing dishes, food or toilet seats.

You cannot get HIV through closed-mouth kissing or saliva. There is little to no risk of getting HIV through oral sex.

CDC, How HIV Spreads . January 2024.
CDC, Preventing HIV. February 2024.
CDC, HIV and Breastfeeding. December 2023.

No. HIV is not spread through casual contact, such as hugging or shaking hands. It also cannot be transmitted by sharing dishes, food or toilet seats.

You cannot get HIV through closed-mouth kissing or saliva.

CDC, How HIV Spreads. January 2024.

As with many other sexually transmitted diseases (STDs), HIV often shows NO symptoms initially. The only way to know if you have HIV is to be tested.

However, some people do get sick during the first weeks after infection. This illness can be confused with the flu. Symptoms may include fever, tiredness, swollen lymph nodes, night sweats, joint and muscle aches, diarrhea and a rash.

When HIV is undiagnosed and untreated, it can cause serious health issues, including death. There is no cure for HIV, but there are highly effective medications, called antiretrovirals (ARVs), that can reduce the amount of virus in the body to undetectable levels. People with HIV who take ARVs as prescribed, and get and keep an undetectable viral load, can live long, healthy lives. When HIV is undetectable, it also cannot be transmitted through sex.

Click here for more about HIV testing.

CDC, About HIV. January 2024.
CDC, Fact Sheet on Acute HIV Infection [PDF].

If you don’t have HIV:

PrEP (pre-exposure prophylaxis): PrEP is a prescribed medication that you take before any potential exposure to HIV. There are two approved forms of PrEP: a daily pill and an injectable provided by a healthcare provider. PrEP is highly effective for preventing HIV when taken as prescribed. Click here to find out more about PrEP.

If you or your partner(s) are living with HIV:

Treatment as prevention: Antiretrovirals (ARVs), prescription medications used to treat HIV, don’t just protect health. HIV treatment also prevents the spread of the virus. The goal with ARV treatment is to lower the amount of virus in the body to a level that is undetectable by standard lab tests. When this happens, HIV cannot be spread through sex. This is also referred to as Undetectable = Untransmittable (U=U). Click here to find out more about HIV treatment.

For anyone:

Condoms: When used consistently and correctly for anal and vaginal sex, condoms are highly effective at preventing HIV. Condoms also protect against many other sexually transmitted diseases (STDs). They are the only form of protection that prevents both pregnancy and disease. Click here to find out more about condoms.

Clean injection equipment: In many cities, there are syringe service programs that offer free, clean syringes. They also provide a safe way to dispose of used syringes. People who inject drugs can also clean their syringes themselves.

For more information:
• How to clean syringes [PDF].
• Find drug treatment programs near you.
• Find a syringe service program near you.

NIH, HIV Undetectable=Untransmittable (U=U), or Treatment as Prevention. May 2019.

No. While there are vaccine trials underway, there is currently no vaccine for HIV, but there are highly effective treatments.

Today, people with HIV who are on antiretroviral (ARV) treatment can live long, healthy lives. ARVs lower the amount of virus in the body. The goal is to reduce the virus to a level that is undetectable according to standard lab tests. When HIV is undetectable, it cannot be transmitted through sex.

HIV treatment also substantially reduces the risk of the pregnant person from passing the virus to the child through pregnancy, childbirth or breastfeeding.

To get all the benefits of ARVs, it is important that someone with HIV stays connected to medical care and takes their medications as prescribed, even if they do not feel sick.

Click here for more about HIV treatment.

Some U.S. states have outdated HIV disclosure laws that don’t reflect the latest research and advancements in HIV prevention and treatment. These laws require you to disclose that you have HIV to sexual partners or people you share drug-injection materials with. Telling these people that you have HIV can protect you legally. Click here to learn about the laws in your state.

Additionally, telling past sexual or drug-injection partners you have HIV is important, so they can get tested and start treatment if they test positive. Letting potential sexual or drug-injection partners about your status can help them make decisions to protect their health.

How to disclose you have HIV:

There are many ways to disclose your HIV status to others.

If you want to tell someone directly, you can tell them in person or through a text, direct message or email.

Many healthcare providers can help reach out to your past sexual or injection partners and let them know that they may have been exposed to HIV. This is often known as partner services. To receive partner services, ask your healthcare provider, local health department or the place that tested you for HIV.

Having trusted friends and/or family who know your HIV status may help you manage your diagnosis. Some things you may want to consider when sharing this information:

• What kind of relationship do you have with this person?
• What are possible outcomes of telling them that you have HIV?
• Will telling them be a safe experience?
• What is that person’s attitude and knowledge about HIV?
• Is there information about HIV you can share that may be helpful?

If you don’t have someone in your life you feel you can share this information with, check out a local support group. You can talk with other people living with HIV and get help from experts. What’s most important is that you get the support and care you deserve!

While many people living with HIV have loving intimate relationships, for some, disclosure can lead to violence. To minimize risk, consider telling them in a public space with others around but private enough to talk. Or, have them talk with a healthcare provider to answer any questions they may have. Learn more about the connection between HIV and intimate partner violence.

CDC, Living with HIV. March 2024.
Well Project, Violence Against Women and HIV. February 2023.

One of the best things you can do is listen without judgment and offer your support.

Allow them to guide the conversation and share the level of detail that is comfortable for them. Let them know you are here to provide whatever help they may need. If they aren’t already in medical care and on treatment for the virus, support them in doing so in offering to help them find a provider, go to medical appointments and/or pick up prescriptions.

Some things to keep in mind if someone tells you they have HIV:

• HIV is not a death sentence. Today, HIV treatment helps people live long, healthy lives. For many, HIV is a chronic, manageable condition.
• HIV is not spread through casual contact.
• It is possible for people with HIV to have healthy sexual relationships with people who do not have the virus. There are more options than ever to prevent the spread of HIV.
• Keep their HIV status confidential.

Your support will help their overall health and well-being.

Sexually transmitted diseases (STDs) are very common. In addition to HIV, the major STDs include chlamydia, gonorrhea and syphilis. These are bacterial infections. Viral infections include herpes and human papilloma virus (HPV), which causes genital warts. Mpox is a virus that also can transmit through sexual contact. Often there are no symptoms of these infections, at least not at first. Left untreated, STDs can cause serious health issues. Also, having one STD can increase the risk of getting another, including HIV.

The good news is STDs, including HIV, are treatable, and many are curable.

Routine testing for many STDs is recommended, but that does not mean it always happens as part of a regular medical checkup or gynecologist exam. To know for sure, ask to be tested.

Click here for more about specific STDs, including symptoms, testing and treatment.

CDC. Sexually Transmitted Infections (STIs). April 2024.

When used consistently and correctly for anal and vaginal sex, latex condoms are highly effective at preventing transmission of HIV and many other sexually transmitted diseases (STDs). Condoms are also the only method of protection that prevents both pregnancy and STDs.

Tips about condoms:

• Check the label of the condom. Don’t use the condom if it is past the expiration date, or if more than five years have passed since the manufacture date.
• Use a new condom if the condom is ripped or looks dry, brittle, stiff or sticky.
• Do not open the condom wrapper with your teeth. This can tear the condom.
• Have extra condoms on hand in case one rips and in case you want to have sex again.
• Do not reuse a condom.
• Keep your condoms in a cool, dry place to prevent breakage or leakage. Don’t store condoms in a location that can get very hot, like in your car.
• Don’t use oil-based lubricants. They can damage the condom. Use a water- or silicone-based lubricant.
• Lubricants are particularly important for use during anal sex. They help prevent the condom from tearing.
• If you keep a condom in your wallet or purse, replace it with a new one every few months.
• Only put a condom on an erect penis. Place the condom on the tip of the penis with the bulb facing outward. Then roll the condom down around the penis.
• After ejaculating during intercourse, pull out your penis before your erection goes away. Hold the condom at the base of your penis to prevent it from slipping off.