HIV/AIDs. HIV is a virus (it stands for Human Immunodeficiency Virus, which means it attacks your immune system). You can have HIV for years and not know it. But eventually it can develop into AIDS, and then you start getting very sick.

With AIDS your body struggles to defend itself against common infections that it would normally fight off easily. So even a cold can become life threatening.

HIV is spread through blood, semen and vaginal fluids. Some people still think of it as a gay disease, but this is plain wrong. Anyone can get it. If you're one of the many people who struggles to believe this, consider the fact that in Africa, AIDS is destroying entire communities as it spreads its way through the heterosexual population, and - worst of all - their children.

Many New Zealanders - straight and gay - have also been infected. In the vast majority of cases, the infection resulted from unprotected sex.

Your best protection against HIV/AIDS during sex is to use a condom. If you have a long term partner and plan to have sex without a condom, then both of you should be checked for HIV/AIDS first. It could be one of the smartest things you do.