The typical course of HIV infection can be described in three phases:

1. Primary infection -1 to 3 months after HIV virus enter the body
2. Clinical latency – on average 8 to 10 years, without antiretroviral treatment
3. Late-stage – Acquired immune deficiency syndrome (AIDS)

If HIV is left untreated, it may take up to 10 or 15 years for the immune system to be so severely damaged that it can no longer defend itself at all. However, the rate at which HIV progresses varies depending on age, general health, and background.