Is it true in some people HIV was unable to be known blood test up AIDS?

It is possible for HIV to go undetected in some people's blood tests until the advanced stages of the disease, known as AIDS (acquired immunodeficiency syndrome). This is because the body's immune system can take several weeks or months to produce detectable levels of antibodies against the virus. During this "window period," a person may be infected with HIV but test negative for the virus on a blood test.

For this reason, it is recommended to get tested for HIV several times, especially if there is any suspicion of potential exposure. If a person is concerned about possible infection, they should get tested immediately and then again a few weeks later to confirm the results.

Early detection of HIV is crucial for timely treatment and management of the infection, which can help slow its progression and improve a person's overall health.