The length of time can vary widely between individuals depending on a person’s health status and behavior. Left without treatment, the majority of people infected with HIV will develop signs of HIV-related illness within 5–10 years, although this can be shorter. The time between acquiring HIV and an AIDS diagnosis is usually between 10–15 years, but sometimes longer. Antiretroviral therapy (ART) can slow the disease progression by preventing the virus replicating and therefore decreasing the amount of virus in an infected person’s blood (known as the ‘viral load’).