If HIV is contracted, after the window period, screening through HIV antibody tests or HIV nucleic acid tests will mostly yield positive results. If the HIV antibody test is positive, an HIV infection can be diagnosed. Once an HIV infection is confirmed, systematic and standardized antiretroviral therapy should be initiated. Systematic and standardized antiretroviral therapy can effectively suppress the virus to undetectable levels, eliminate infectiousness, gradually enhance immunity, and allow one to live a normal lifespan.