Acquired Immunodeficiency Syndrome (AIDS): The most advanced phase of infection with HIV (human immunodeficiency virus) in which the immune system is weakened The person becomes more susceptible to a variety of infections (called opportunistic infections) and other conditions such as cancer A diagnosis of AIDS is made based on clinical criteria and/or the results of blood tests Specifically, AIDS is diagnosed when a person living with HIV has a CD countless than 200 cells/mm3 or has an AIDS-defining condition (NYC DOHMH)
