What Are Your Odds of Getting HIV?

What Are Your Odds of Getting HIV?

What Are Your Odds of Getting HIV?
Richard Drury/Getty Images
By
and
Updated on November 21, 2025
by

The transmission risk of human immunodeficiency virus (HIV) varies by the type of exposure. But proven tools can help make getting HIV preventable.

As scientists continue to investigate and evaluate different levels of risk, prevention techniques such as pre-exposure prophylaxis (PrEP), post-exposure prophylaxis (PEP), and antiretroviral therapy for people living with HIV continue to make advances.

If you think you may have been exposed to HIV or have questions about your risk, talk to your doctor right away. Early testing and treatment are the best ways to protect your health and prevent transmission to others.

Odds of Getting HIV From Anal Sex

Receptive anal sex without a condom poses the highest HIV transmission risk of any sexual act. Omar Harfouch, MD, MPH, a physician and researcher who specializes in HIV treatment and prevention at the Institute of Human Virology at the University of Maryland School of Medicine in Baltimore, says that the odds of transmitting HIV this way are between about 0.5 and 1.4 percent. That means that the probability of acquiring HIV from an infected person in that way is roughly 138 out of every 10,000 exposures.

The insertive (“top”) partner is about 12.5 percent less likely than the receptive partner (“bottom”) to get HIV from someone with HIV. The risk is 0.1 percent or less, Dr. Harfouch says.

That’s because HIV is found in blood, semen, preseminal fluid, and rectal fluids, and it can cross the rectum’s thin lining with relative ease. Bodily fluids carrying the virus can also enter the insertive person through the urethra (the opening at the tip of the penis) or any cuts or sores on the penis.

Odds of Getting HIV From Vaginal Sex

Women account for 18 percent of new HIV diagnoses, as of 2021. The most common way that women get HIV is through sex without a condom with a male partner who has HIV.

Receptive vaginal intercourse, receiving the penis into the vagina, has a 0.08 percent risk, Harfouch says.

 A man with HIV can transmit the virus to a female partner through preseminal fluid or semen because the virus can pass through the lining of the vagina and cervix.
A woman living with HIV also can transmit the virus to a male partner through vaginal fluid and blood, because the virus may pass through the urethra, the foreskin (if the man isn’t circumcised), or open sores on the penis. The risk of transmitting HIV through insertive vaginal intercourse, inserting the penis into the vagina, is 0.04 percent, Harfouch says.

How to Lower Your Risk of Getting or Spreading HIV

Learn about how to protect yourself and others from HIV infection.
How to Lower Your Risk of Getting or Spreading HIV

Next up video playing in 10 seconds

Odds of Getting HIV From Oral Sex

The odds of getting HIV during oral sex are low, according to the Centers for Disease Control and Prevention (CDC). The virus isn’t transmitted through saliva (or tears or sweat) unless it’s also mixed with blood. But if a man who has HIV ejaculates in a partner’s mouth and, for example, the partner has an open sore or bleeding gums, it is theoretically possible to pass along the virus.

People can reduce this risk by having a male partner ejaculate into a condom or by removing their mouth from the penis before ejaculation.

Odds of Getting HIV From Shared Needles

People who inject drugs face a 0.6 percent risk of getting HIV if they use and share needles, syringes, or other drug-injection equipment that someone with HIV has also used.

Using shared injection equipment and needles for steroids, hormones, piercings, and tattoos also poses a risk of transmitting HIV. All of these items can contain blood, so HIV could be transmitted to another person’s bloodstream. In the right environmental circumstances, the virus can survive in a used needle as long as 42 days.

In addition, drug use can lower inhibitions, making people less likely to use a condom during sex or to take medications that can prevent HIV from taking hold after an exposure, further increasing the risk of transmission.

Odds of Getting HIV From Other Sources

There are numerous other ways in which HIV can be transmitted, though most have a minute risk.

Although transfusing blood with HIV directly into another person’s bloodstream carries a 92.5 percent probability that HIV will be transmitted, that risk is exceedingly rare in practice.

 A China-based study placed the odds of getting HIV through a blood donation at less than 1 in 1 million.

The CDC says that it is technically possible but never scientifically proven to get HIV through these practices:

  • Biting
  • Spitting
  • Sharing sex toys
HIV can also spread from a mother to a child during pregnancy or childbirth. With treatment, however, the risk of transmission is less than 1 percent.

What to Do if You Are Exposed to HIV

“If you think you might be at risk for HIV, talk to your healthcare provider,” Harfouch says.

If you have been exposed, you may be able to take an emergency medication called PEP that can lower your odds of infection.

Because HIV can establish itself within 24 to 36 hours of exposure, it is important to start PEP as soon as possible. It is recommended only within the first 72 hours after exposure, and it is not meant to be a substitute for other HIV prevention methods. If you are prescribed PEP, you are advised to take it for 28 days.

How to Lower Your Risk of Getting or Spreading HIV

If you’re at a high risk of infection — for example, if your current sexual partner has HIV — taking an oral or injectable medication called PrEP can lower your risk of contracting HIV from sex by about 99 percent.

PrEP pills can also cut the risk of transmission among people who inject drugs by more than 74 percent. PrEP injections are not recommended for people who inject drugs.

 In addition to taking PrEP, people who inject drugs can lower their HIV risk by using sterile needles and syringes. These can be obtained without a prescription at pharmacies and through syringe programs by state or local health departments.

To find substance abuse help, call the Substance Abuse and Mental Health Services Administration’s national helpline at 800-662-HELP (4357) or visit its website for a list of treatment facilities near you.

When used correctly, condoms can also lower the risk of transmitting HIV as well as other sexually transmitted infections (STIs), including syphilis, herpes, gonorrhea, and chlamydia. If a sexual partner has an untreated STI or an infection such as bacterial vaginosis, the risk of getting HIV increases as much as 8 times. To decrease your risk of HIV, it’s important to be tested for STIs, too.

If you have HIV, you can drastically reduce the odds of passing along the virus by taking antiretroviral therapy (ART). These medications can lower the amount of HIV that resides in the body, called viral load, to a level that’s undetectable by modern testing. People with HIV who take ART as prescribed and keep an undetectable viral load do not transmit HIV through sex.

The Takeaway

  • The probability of getting HIV varies based on the type of exposure, with unprotected anal sex holding the highest risk.
  • Preventive measures such as pre-exposure prophylaxis, post-exposure prophylaxis, and consistent antiretroviral therapy can drastically reduce the risk of transmission and are crucial for those at high risk.
  • If you suspect that you have been exposed to HIV, seek medical advice immediately, as post-exposure treatment must occur within 72 hours of exposure.
  • Using sterile needles, practicing safe sex using condoms, and adhering to prescribed HIV medications can help yourself and reduce the overall spread of the virus.

Resources We Trust

EDITORIAL SOURCES
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
Resources
  1. Tanner MR et al. Antiretroviral Postexposure Prophylaxis After Sexual, Injection Drug Use, or Other Nonoccupational Exposure to HIV — CDC Recommendations, United States, 2025. Centers for Disease Control and Prevention. May 8, 2025.
  2. About HIV. Centers for Disease Control and Prevention. January 14, 2025.
  3. HIV and Specific Populations. National Institutes of Health. September 4, 2024.
  4. Risk of Exposure to HIV/AIDS. Stanford Medicine.
  5. HIV Risk Reduction Tool. Centers for Disease Control and Prevention. June 14, 2022.
  6. Zhu H et al. Prevalence and Residual Risk of HIV in Volunteer Blood Donors of Zhejiang Province, China, from 2018 to 2022. The Canadian Journal of Infectious Diseases. May 24, 2024.
  7. Preventing Perinatal Transmission of HIV During Pregnancy and Childbirth. National Institutes of Health. May 28, 2025.
  8. Clinical Guidance for PEP. Centers for Disease Control and Prevention. February 10, 2025.
  9. PrEP. Centers for Disease Control and Prevention. February 18, 2025.
Meet Our Experts
See Our Editorial PolicyMeet Our Health Expert Network
John-Paul-McHugh-bio

John Paul McHugh, MD

Medical Reviewer
Member of American College of Lifestyle Medicine

John Paul McHugh, MD, is an obstetrician-gynecologist and lifestyle medicine specialist in southern California. He has always placed wellness at the center of his work, in both delivering babies and improving practice standards. Dr. McHugh believes that bringing lifestyle medicine to the center of health and wellness empowers patients to make the change they seek and enjoy the benefits of true wellness.

He is a graduate of Harvard Medical School and the Massachusetts Institute of Technology and a fellow of the American College of Lifestyle Medicine. He served as a department chair at Scripps Mercy Hospital in San Diego and is now the chair-elect for the American College of Obstetricians and Gynecologists for California.

He has published several articles in the American Journal of Lifestyle Medicine and served as a peer reviewer for many articles. He contributed to the first textbook of lifestyle medicine in women's health: Improving Women's Health Across the Lifespan.

See full bio
Becky Upham, MA

Becky Upham

Author

Becky Upham has worked throughout the health and wellness world for over 25 years. She's been a race director, a team recruiter for the Leukemia and Lymphoma Society, a salesperson for a major pharmaceutical company, a blogger for Moogfest, a communications manager for Mission Health, a fitness instructor, and a health coach.

Upham majored in English at the University of North Carolina and has a master's in English writing from Hollins University.

Upham enjoys teaching cycling classes, running, reading fiction, and making playlists.

See full bio
Maria Masters

Maria Masters

Author

Maria Masters is a contributing editor and writer for Everyday Health and What to Expect, and she has held positions at Men's Health and Family Circle. Her work has appeared in Health, on Prevention.com, on MensJournal.com, and in HGTV Magazine, among numerous other print and digital publications.

See full bio
See Our Editorial PolicyMeet Our Health Expert Network