"HIV" stands for Human Immunodeficiency Virus. HIV targets and kills CD4 cells of the immune system, making one easier to get certain types of infections and cancer.

If left untreated, HIV infection can progress to AIDS (Acquired Immunodeficiency Syndrome), which is the most advanced stage of HIV infection. Due to the extreme depletion of CD4 cells in AIDS patients, these individuals are significantly more susceptible to a wide range of cancers and opportunistic infections, which take advantage of a weakened immune system and are uncommon in healthy individuals.

Although currently there is no cure for HIV infection, there is effective drug treatment to keep the virus under control. With early diagnosis and effective treatments, most people with HIV can live a long and healthy life without developing any AIDS-related illnesses. This means that they can live a near-normal lifespan.

AIDS (Acquired Immunodeficiency Syndrome)  is caused by HIV. Without treatment, about half of HIV infected people will progress to AIDS within 10 years. On the contrary, HIV treatment prevent AIDS and significantly prolongs life expectancy. Not everyone who has HIV experiences this stage.

Once progress to this stage, the immune system is seriously damaged. The infected person is more vulnerable to certain cancers and a wide range of infections, such as Pneumocystis pneumonia (PCP), tuberculosis (TB) and fungal infections or certain cancers.

HIV treatment is the only way to prevent from progressing to AIDS.