HIV weakens the immune system and can lead to AIDS if untreated. HIV is transmitted through bodily fluids and can be spread sexually, through sharing needles, or from mother to child. While some experience flu-like symptoms soon after infection, many feel healthy yet slowly develop AIDS without medication over 10 years on average. Late-stage AIDS leaves one vulnerable to serious illness. Testing and antiretroviral treatment can prevent and manage HIV/AIDS. World AIDS Day aims to raise awareness and support for all those affected.