First aid, right now

CDC’s advice for anyone splashed with blood or cut by a used sharp is:

  1. Cuts and puncture wounds: wash with soap and water.
  2. Splashes to the nose, mouth or skin: flush with water.
  3. Eyes: rinse with clean water, saline or a sterile eyewash.
  4. At work: report the incident to your supervisor.
  5. Get medical care right away so a clinician can assess the risk.

Then work out where the blood landed, because that decides whether there’s any risk at all.

Where the blood landed matters

HIV can only get into your body through a mucous membrane (the moist lining of the eyes, nose, mouth, vagina, rectum or penis), through damaged tissue, or by being injected into the bloodstream. Skin is a strong barrier.

  • Unbroken skin: no risk. Blood on your hands, arms or face, where the skin isn’t cut or broken, can’t give you HIV. Wash it off and move on.
  • Fully healed cuts: healed skin is intact skin, so there’s no risk.
  • A fresh, open cut or wound: a small risk if the blood came from someone with HIV.
  • Eyes, inside the nose or mouth: a small risk if the blood came from someone with HIV.

How big is the risk?

For blood from someone with HIV who isn’t on effective treatment reaching your eyes, mouth or an open wound, the calculator uses an estimate from studies of healthcare workers: 0.09% (about 1 in 1,100). That is lower than a needlestick, which is 0.23% (about 1 in 430).

Most of the time you won’t know whether the person had HIV. If you don’t, the estimate also depends on how common HIV is where you are. For a splash from someone of unknown status in the United States, it’s 0.00036% (about 1 in 280,000). In South Africa, where HIV is more common, it’s 0.015% (about 1 in 6,500).

Common situations

A fight or a sports injury. If someone else’s blood got into an open wound or your eyes, use the steps above and get advice the same day. If it only touched your skin, there’s no risk.

Giving first aid. Blood on intact hands carries no risk. Use gloves when you can, and wash afterwards.

A nosebleed or a cut while sharing a space is not an exposure unless the blood reached your eyes, mouth or an open wound.

Saliva, sweat or tears in your eyes or mouth carry no risk. HIV isn’t transmitted through them.

PEP after a blood exposure

PEP (post-exposure prophylaxis) is HIV medicine taken daily for 28 days to stop an infection from taking hold. It must start within 72 hours, ideally within 24. A clinician will weigh where the blood landed, how much there was and what is known about the other person. They will tell you whether PEP is recommended for your situation. Go even if you think the risk is small: that decision is easier to make with them than alone.

At work, it may be possible to test the source person with their consent, which can settle the question quickly.

What to do now

Blood in your eyes, mouth or an open wound in the last 72 hours? If the person has HIV or might, go to an emergency department or urgent care today and ask about PEP. How to get PEP

  • Only on unbroken skin? You don’t need PEP or a test because of it.
  • More than 72 hours ago? PEP is no longer recommended, but you can test. The HIV test accuracy by week page shows when each test gives a reliable result.
  • Cut by a used needle or sharp? That’s a different exposure with a higher risk. See needlestick injuries.