HIV stands for Human Immunodeficiency Virus. HIV weakens your immune system, and makes it much harder for your body to fight off infections. When HIV progresses, it can lead to Acquired Immune Deficiency Syndrome (AIDS). AIDS is the most advanced form of HIV; people with AIDS are even more at risk of specific complications like infections and cancers.

Fortunately, wonderful treatments exist to keep your immune system strong. By starting on treatment early and staying on it, HIV is now a manageable, chronic condition. Tremendous progress has been made, and continues to be made, to the point where people with HIV can expect to have a nearly normal lifespan if they continue to take their medicines the right way.

Risk of HIV is not the same for all sex acts. While PrEP for HIV-negative people and maintaining an undetectable viral load through taking medications for HIV-positive men both prevent HIV transmission, it’s still good to know what the different levels of risk are, since you may not always know your partner’s HIV prevention strategy.

If someone is HIV-positive and has an undetectable viral load, they effectively cannot transmit HIV. If someone became HIV-positive recently or is not taking medications, the odds of HIV transmission are much greater.  It’s important to remember that someone could be living with HIV and not know it. That’s why it’s important to get tested regularly.

If you don’t have HIV and you’re not on PrEP or you do have HIV and don’t have an undetectable viral load (or if you don’t know if your partner is on PrEP or has an undetectable viral load), here is information on transmission of HIV through different kinds of sex.

No risk for HIV transmission:
Kissing, mutual masturbation, rimming, frottage, massage, water sports, bondage, dirty talk and role play, spanking, wrestling.

Little to no risk for HIV transmission:
Oral sex.

Medium risk for HIV transmission:
Topping without a condom.

High risk for HIV transmission:

  • Bottoming without a condom, sharing needles and/or works during IV drug use, and needle play with shared needles.

Of course, these ranges apply only to HIV, not for other STIs such as syphilis, gonorrhea, chlamydia, or hepatitis. Some STIs can be transmitted through skin-to-skin contact in areas not covered by a condom. COVID-19 can be prevented by vaccination, booster shots, masking, and ventilation.

While there are several behaviors that are no risk or low risk for HIV transmission, remember: the most common method of HIV transmission is bottoming without a condom, unless the negative partner is on PrEP or the positive partner is on HIV medication with an undetectable viral load.

Can I get HIV from kissing?


What’s the likelihood of getting infected through oral sex?

  • From giving a blow job: Oral sex is MUCH less risky than anal or vaginal/front hole sex – but HIV still can enter through small open cuts or sores. There are some documented cases of people getting HIV through their mouth. Researchers agree it’s extremely, extremely rare.
    • Once semen gets past the mouth, stomach acid and enzymes in the esophagus kill the virus. So, swallowing or spitting out semen (cum or precum) might reduce your risk for HIV, compared with letting it sit in your mouth.
    • To reduce your risk even more, make sure you keep the mucous membranes in your mouth healthy – don’t give head for about 45 minutes after you brush your teeth, floss, or engage in any other aggravating oral behavior, and not at all when you have open sores. Remember, while the chance of getting HIV from oral sex is extremely low, you can easily get other STIs.
  • From getting a blow job:  There are no cases reported, so most likely zero.  There is a risk, however, of getting other STIs.
  • Rimming: Minimal to none. However, there is a risk of getting other STIs including hepatitis.

For more information about the statistical likelihood of a specific sexual act and to estimate your own risk, click here.

Treatment as Prevention (TasP) is a strategy people who are HIV-positive can use to prevent the spread of HIV. When people who are living with HIV take their HIV medications as prescribed and maintain an undetectable viral load, they have zero risk of passing on HIV to their HIV-negative sexual partners.  We do not yet know if TasP is as effective in preventing HIV transmission through sharing needles or injection drug equipment.

How do we know it works? There are two big clinical trials that have provided definitive evidence that treatment as prevention is effective (HPTN 052 Study and PARTNER Study).

U=U (Undetectable = Untransmittable) means that a person living with HIV who has an undetectable viral load cannot pass HIV on to their partners. U=U is a term that has been adopted by many HIV organizations around the world. For more information, check out the Prevention Access Campaign.

Keep in mind that when an HIV-positive person first starts on treatment, it can take several months before their viral load is completely suppressed.

When someone goes from being HIV-negative to being HIV-positive, we say that they have “seroconverted.” Right after someone has contracted HIV, the person might experience something called “acute HIV infection,” which may feel like a bad flu that lasts for a couple of weeks. Some of the symptoms include fever, rashes, a sore throat, and swollen glands. However, not everyone gets these symptoms.

After experiencing seroconversion illness, the person will probably test positive on HIV tests that detect antibodies to HIV. It takes a few weeks or months for someone who’s been infected with HIV to develop antibodies to the virus.

After seroconversion illness, a person with HIV might experience other symptoms like unexplained diarrhea, weight loss, rashes, or fevers. If HIV is left untreated over a period of time, a HIV-positive person can develop AIDS, and may get AIDS-related illnesses like pneumonia, brain infections, skin cancers, and severe fungal infections.

There is no vaccine or cure for HIV. People with HIV take medications, called antiretrovirals, that help them stay healthy. People with HIV who take antiretrovirals can live long and healthy lives. If HIV isn’t treated, it can lead to AIDS and eventually death.

Antiretroviral medications (sometimes called antiretroviral therapy or ART) treat HIV by attacking the virus at different points in its life cycle and preventing HIV from replicating. They don’t eliminate HIV completely from the body, but they can keep the amount of HIV in the body at a low level. This limits damage to the immune system and helps the immune system recover to some extent from any damage caused by HIV. It also prevents the person living with HIV from transmitting HIV to anyone else.

It is recommended that people start ART immediately after being diagnosed. Research shows that people who start treatment early can expect to have a normal lifespan, particularly if diagnosed soon after they’ve become positive. That’s one reason frequent testing is so important.

Undetectable – what does it mean?

The term “undetectable viral load” pops up everywhere from lab reports and medical journals to social media sites and dating apps.

Here are some key terms and concepts to help people living with HIV and HIV-negative folks understand and explore what “undetectable” means.

Key Terms

Viral load
Viral load refers to how many copies of HIV are present in a milliliter sample of blood. A viral load test estimates how much HIV is in the blood. It is used to monitor immune function and see how well HIV treatment is working.

Antiretroviral therapy (ART)
ART involves taking medications to keep the virus from replicating in an HIV-positive person’s cells. Taking ART decreases viral load.

Undetectable viral load
When copies of HIV cannot be detected by standard viral load tests, someone living with HIV is said to have an “undetectable viral load.” For most tests used in clinics today, “undetectable” means fewer than 50 copies of HIV per milliliter of blood. Reaching an undetectable viral load is a key goal of ART.

Short for “pre-exposure prophylaxis,” PrEP is an HIV prevention strategy in which HIV-negative people take an oral pill once a day or following the “2-1-1” strategy, whichever is easiest for you.

PrEP 2-1-1 involves taking PrEP medication around times of anal sex instead of once per day. PrEP 2-1-1 is named for its schedule of dosing: You take two pills 2-24 hours before sex, one pill 24 hours after the initial dose, and one final pill 24 hours later. Take two pills to reduce their risk of HIV infection.

Being Undetectable
Good news! You can live a healthier and longer life. Using ART to reach an undetectable viral load means that there is less HIV in your body. Less HIV means less damage to your immune system, allowing you to stay healthier and live longer.

You can reduce HIV transmission risk
Studies have shown that people with an undetectable viral load have effectively no risk of transmitting the virus to their HIV-negative partners. More people on effective treatment and with their virus in check means more HIV infections are prevented—an approach called “treatment as prevention,” or TasP.

A Few Words of Caution

“Undetectable” does not mean “cured.” An undetectable viral load means that so few copies of the virus are present in the blood that today’s monitoring tests are unable to detect them. Even with an undetectable viral load, however, an HIV-positive person still has the virus.

Keep in mind that after starting treatment it can take several months before viral growth is completely suppressed. During that time, it’s a good idea to use condoms and/or make sure your partner is on PrEP.

While suppressing the virus to undetectable levels has clear benefits for both people living with HIV and HIV-negative people, treatment as prevention is just one strategy for preventing new HIV infections. Other essential tools for HIV prevention include condoms, sterile syringes for people who inject drugs or hormones, PrEP for HIV-negative individuals, regular HIV testing, self-education about HIV and sexual health, and open communication with sex partners.