AIDS, or Acquired Immunodeficiency Syndrome, is the final and most severe stage of HIV infection. At this point, HIV has caused serious damage to the immune system, leaving the body vulnerable to infections and illnesses that it would normally be able to fight off. These illnesses are called opportunistic infections or AIDS-defining conditions because they take advantage of the body’s weakened defenses.
A person is diagnosed with AIDS when their CD4 cell count – the type of white blood cells that help fight infections – drops below 200 cells per cubic millimeter of blood (cells/mm³). A diagnosis can also be made if someone develops certain serious infections or cancers that are linked to advanced HIV disease, regardless of their CD4 count.
When HIV has progressed to AIDS, the viral load in the blood is often very high, making it much easier to transmit the virus to others through blood, sexual contact, or other means. Without proper treatment, the immune system continues to weaken, and the body struggles to recover from even minor illnesses.
Without antiretroviral therapy (ART), people with AIDS typically survive about three years. However, if a person develops a dangerous opportunistic infection, survival time without treatment can be even shorter. The good news is that with the right medical care and consistent treatment, people diagnosed with AIDS can still live longer, healthier lives. Starting or resuming ART can help rebuild the immune system and greatly improve quality of life.