In people who are undergoing drug therapy for HIV, their level of immunity remains strong enough to prevent the condition from progressing to AIDS. With current treatment options, AIDS is unlikely to develop.
Without treatment, however, the viral load can increase, and the CD4 cell count can drop. This reduced immunity leaves the body susceptible to various infections and diseases, which can be life-threatening. An AIDS diagnosis is made when the CD4 cell count of someone with HIV drops to under 200. A healthy CD4 count is between 500 and 1,500 cells per millimeter cubed (cells/mm3). Alternatively, the development of one or more opportunistic infections can also indicate that the HIV infection has progressed to AIDS.