AIDS is a viral infection caused by HIV (Human Immunodeficiency Virus). This virus is able to gradually destroy the affected person's immune system, which over time is no longer able to defend itself against attacks by bacteria, viruses and other external agents. When a person comes into contact with the HIV virus, he/she may or may not be contaminated, but if he/she does contract the infection, he/she may not get sick right away. The virus propagates in its host organism, which initially resists by producing antibodies (Ab). If these antibodies are present when a blood test is performed, the person is defined as a seropositive. Unlike those that occur in other infections, these antibodies do not constitute a defense mechanism but only represent a sign of infection in progress.

It is possible to be HIV-positive for many years without any symptoms, but the virus continues its work of destroying immune defenses until the person becomes ill (full-blown AIDS). At this point, the slightest infection, even the most trivial, can be fatal. The progression of the disease is not the same for everyone, but it also depends a lot on the lifestyle of the person who has HIV. If an HIV-positive person lives a normal life in the sense that he or she has adequate hygiene, sleeps a sufficient number of hours, eats in a healthy and regular manner, does not drink, does not smoke, tries to avoid particularly stressful situations and is surrounded by the love and affection of his/her loved ones, he/she will surely have a longer life expectancy than a drug addict or a person who lives in objectively unstable conditions, and whose immune system is already undermined by drugs and stress.

ALWAYS use a condom during sexual intercourse; this is the most effective way to protect yourself from AIDS and other sexually transmitted diseases. It is best to use prudence in choosing your sex partner, especially if he/she is occasional and not unique (multi-partner sexual relationships). Don't let yourself be persuaded by thinking "why would it happen to me?" Make sure to take all necessary precautions. Be careful not to get infected with blood through small wounds in the skin and/or the mucous membranes.

Do not swap toothbrushes, razors or other personal effects. Observe the normal hygiene standards of common social life. These represent the necessary precautions to be taken to protect yourself from the risk of an HIV infection, and are also valid for any infection that can be transmitted through unprotected sex.