HIV and AIDS is a serious disease of the immune system that is transmitted through bodily fluids like blood, semen, and breast milk. It was first recognized in the 1980s in the US in gay men. Common ways it spreads include unprotected sex, sharing needles, from mother to child during birth or breastfeeding. Having HIV damages the immune system by affecting T-cells, which can lead to infections like pneumonia. In the UK in 2009, around 86,500 people lived with HIV and there were 6,630 new cases. Globally, the number of people living with HIV rose to 33 million by 2009, though new infections and deaths have declined due to treatment. Prevention methods include getting tested, using condoms, not sharing