Skip navigation

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

URL of this page:

HIV and Infections

Also called: AIDS-related opportunistic infections, OIs


What are opportunistic infections (OIs) in HIV?

Having HIV weakens your body's immune system. It destroys the white blood cells that fight infection. This puts you at risk for opportunistic infections (OIs). OIs are serious infections that take advantage of your weak immune system. These infections are less common and less severe in healthy people.

People who have AIDS, the most severe stage of HIV infection, have badly damaged immune systems. This puts them especially at risk for OIs. Getting certain OIs is one of the ways that people can get diagnosed with AIDS.

OIs are becoming less common in people with HIV because of effective HIV medicines. But some people with HIV still develop OIs for different reasons:

  • They may not know they have HIV, so they aren't getting treatment for it
  • They know that they have HIV but are not taking treatment
  • Their HIV treatment may not be working properly

What are the different types of opportunistic infections (OIs)?

There are many types of OIs:

Having HIV can make infections harder to treat. People with HIV are also more likely to have complications from common illnesses such as the flu.

What are the treatments for opportunistic infections (OIs)?

If you develop an OI, there are treatments available such as antiviral, antibiotic, and antifungal drugs. The type of medicine your health care provider prescribes will depend on which OI you have.

After the OI has been successfully treated, you may still need to take the same medicine or another medicine to prevent the OI from coming back.

Can opportunistic infections (OIs) be prevented?

The best way to prevent OIs infections is by taking your HIV medicines. Other steps you can take to help prevent OIs include:

Start Here

Prevention and Risk Factors

Treatments and Therapies

Related Issues


Clinical Trials

Reference Desk

  • Glossary From the National Institutes of Health (; National Institutes of Health, Office of AIDS Research)

Find an Expert

Patient Handouts

The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.