HIV/AIDS & Immunodeficiency

HIV progressively destroys CD4+ T-cells, weakening the immune system's ability to fight infection over time — disease stage is tracked largely by CD4 count, with a count below 200 cells/mm³ defining progression to AIDS (acquired immunodeficiency syndrome), the stage at which opportunistic infections (such as Pneumocystis jirovecii pneumonia, candidiasis, and certain cancers like Kaposi sarcoma) become significantly more likely. Antiretroviral therapy (ART), typically a combination of medications from different drug classes, suppresses viral replication, allows CD4 counts to recover, and — when taken consistently and achieving an undetectable viral load — dramatically reduces both disease progression and the risk of transmission to others; medication adherence is therefore one of the single most important teaching priorities, since inconsistent dosing promotes viral resistance and treatment failure.