For what length of time can hiv possitive person survive?

As long as anyone: Hiv infection has become a chronic disease that has become more easily managed (if caught early and treated with anti-hiv meds), similar to high blood pressure or diabetes. For many people, HIV is no longer a death sentence. Thus, as long as a person continues to take care of themselves and takes the antihiv meds, they should be able to live as long as anyone else.