“AIDS” stands for Acquired immunodeficiency syndrome. It is the most severe phase of HIV infection. People with HIV classified as stage 3 AIDS have such badly damaged immune systems that they get an increasing number of severe illnesses, called opportunistic illnesses.
Without treatment, people with HIV classified as stage 3 (AIDS) typically survive about 3 years. Common symptoms of stage 3 (AIDS) include chills, fever, sweats, swollen lymph glands, weakness, and weight loss.
People are classified as stage 3 (AIDS) when their CD4 cell count drops below 200 cells/mm or if they develop certain opportunistic illnesses. People with HIV classified as stage 3 (AIDS) can have a high viral load and be very infectious (also see: HIV).