In plain words
HIV is a virus that attacks the immune system. AIDS is the most advanced stage of infection. HIV weakens white blood cells, making it easier to get illnesses such as tuberculosis, other infections and some cancers.
There is no cure, but with effective prevention, diagnosis, treatment and care it is now a manageable long-term condition.
Key facts
- WHO estimated 41.0 million people were living with HIV at the end of 2025, 64% of them in the WHO African Region.
- In 2025 about 570,000 people died of HIV-related causes and about 1.2 million acquired HIV.
- In 2025, 88% of people with HIV knew their status, 89% of those were on antiretroviral therapy (ART) and 95% of those on ART had suppressed viral loads.
How it spreads
Through blood, breast milk, semen and vaginal fluids of an infected person, and from mother to baby. It is not spread by kisses, hugs or sharing food.
Signs and symptoms
Early on there may be no symptoms, or an influenza-like illness with fever, headache, rash and sore throat. Later signs include swollen lymph nodes, weight loss, fever, diarrhoea and cough. Without treatment, severe illnesses can develop, including tuberculosis, cryptococcal meningitis, severe bacterial infections, lymphomas and Kaposi sarcoma. HIV is more easily spread in the first months after infection, and many people do not know their status until later stages.
Treatment
HIV can be prevented and treated with ART. Untreated HIV can progress to AIDS, often after many years. WHO defines advanced HIV disease as a CD4 count below 200 cells/mm3 or a WHO stage 3 or 4 event in adults and adolescents, and all children under 5 with HIV are considered to have it.
Sources
- WHO fact sheet, HIV, published 27 July 2026, read 9 October 2026.
Last reviewed: 9 October 2026. Reviewer: none yet. This page is general education and is not medical advice. Figures are WHO's and may have been updated since.