HIV stands for Human Immunodeficiency Virus. HIV is the virus that causes AIDS (Acquired Immune Deficiency Syndrome). It attacks the immune system’s soldiers - the CD4 cells. When the immune system loses too many CD4 cells, you are less able to fight off infection and can develop serious opportunistic infections (OIs). A person is diagnosed with AIDS when he or she has less than 200 CD4 cells and/or one of 21 AIDS-defining OIs.

AIDS is the most advanced stage of HIV infection. AIDS is not caused by party drugs, AZT, government conspiracies, or anything else but a virus. When someone dies of AIDS, it is usually opportunistic infections or other long-term effects of HIV infection that cause death. AIDS refers to the body’s immune-compromised state that can no longer stop OIs from developing and becoming so deadly.

People don’t have AIDS as soon as they are infected with HIV. they can be HIV+ for many years with no signs of disease, or only mild-to-moderate symptoms. But without treatment, HIV will eventually wear down the immune system in most people to the point that they develop more serious OIs.

There is only one reliable way to find HIV status and that is to take the HIV test. The most common test is an antibody test called ELISA. A positive result means you have antibodies for HIV and you are infected with the virus. Most people can not tell that they have been exposed or infected. It can take up to 12 weeks for an HIV test to come back positive. However most people respond much faster. Within two to four weeks of exposure to HIV, you might have flu-like symptoms such as fever, swollen glands, muscle aches, or rash.

There is no cure for HIV. But there are drugs that can slow down the virus and protect your immune system. There are also drugs to treat and prevent OIs. Being unaware of your status also makes it more likely to unknowingly pass HIV to others.

HIV is only spread through the Blood, Semen, Vaginal fluids, Breast milk and the most common ways HIV is passed from one person to another are Reusing and sharing needles,
Unprotected sex, Mother-to-child, During pregnancy, during birth, or through breastfeeding. HIV cannot be spread through tears, sweat, and saliva. Casual contact is not risky because it does not include contact with infectious body fluids. Examples of casual contact include: social kissing, use of public facilities (pools, theaters, bathrooms), sharing drinks or eating utensils, etc. Insect bites do not transmit HIV.

Listed from most to least risky

• Receptive anal sex (”bottoming”) remains the most risky activity, due to the likelihood of direct semen-blood contact. But penetrative anal sex (”topping”) with someone can result in HIV transmission, too.
• Vaginal intercourse puts both partners at risk, but HIV is transmitted from men to women much more easily than from women to men. 
• Oral sex can be risky for the person performing it, particularly if he or she swallows semen, vaginal fluids, or menstrual fluids. 
• Sharing sex toys without sterilizing them can be dangerous. 
• Rimming (licking the anus) is very unlikely to result in HIV infection. 
• Mutual masturbation (hand jobs) and fisting (using a hand to penetrate the anus or vagina) are relatively risk-free, as long as your hand has no open cuts or sores. 
• Sexual assault can result in infection if the assailant is HIV+. The risk increases when rape involves anal penetration, force, and/or multiple assailants. Some forced sexual acts involving wounds can place a victim at very high risk.