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Acquired immunodeficiency syndrome (AIDS)

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Acquired immunodeficiency syndrome (AIDS)

Acquired immunodeficiency syndrome (AIDS) is the most severe stage of HIV infection. HIV attacks and destroys a type of white blood cell called CD4+ cells, or helper cells. These cells are an important part of the immune system. If HIV is not treated, it will usually get worse over time and cause AIDS.

A person who has HIV is diagnosed with AIDS when they have one or both of the following:

  • A CD4+ cell count below 200 cells per microliter (mcL) of blood.
  • Certain infections or cancers that are usually seen only in people who have problems with their immune system. Examples include infections such as Pneumocystis pneumonia and cancers such as Kaposi sarcoma.

Treating HIV can help the immune system stay healthy. This may delay or prevent AIDS.

Current as of: April 30, 2024

Author: Ignite Healthwise, LLC Staff

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This information does not replace the advice of a doctor. Ignite Healthwise, LLC, disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. Learn how we develop our content.

NOTICE: This health information was not created by Columbia University Irving Medical Center and may not necessarily reflect specific CUIMC practices. For medical advice to your personal condition, please consult your doctor. Medical advice disclaimer.