Once HIV enters the human body, the virus progresses through three stages of infection.

Within 2 to 4 weeks after infection, people may experience a flu-like illness, which may last for a few weeks. Individuals with acute HIV infection have a large amount of virus in their blood and are very contagious.

During this phase, HIV is still active but reproduces at very low levels. People may not show any symptoms or feel sick during this time, but they can still pass the virus to others.

Left untreated, HIV eventually increases its presence in the human body, causing a person’s CD4 cell count to drop drastically, thus leaving the body highly vulnerable to opportunistic infections. This – the most severe phase of HIV infection – is what is known as “AIDS”. Common symptoms of AIDS include chills, fever, sweats, swollen lymph glands, weakness, and weight loss.

Without treatment, people with AIDS typically survive about 3 years. However, new medications known as antivirals can inhibit HIV and can slow or prevent progression from one stage to the next. These medications can also dramatically reduce the chance of transmitting HIV to someone else.