hiv and aids  symptoms, treatment, and causes
AIDS is a term applied to advanced HIV disease. AIDS is defined as having HIV and an opportunistic infection (an infection by a microorganism that ordinarily does not cause disease unless the immune system is weakened) normally associated with AIDS. These infections can be bacterial, fungal, viral, or parasitic.
The virus can pass from person to person through contact with infected blood, semen, or vaginal fluids. Having unprotected sex with an infected partner increases your risk of infection. Other risk factors for HIV/AIDS include having a blood transfusion and sharing needles or syringes with an infected person.