Acquired Immune Deficiency Syndrome/ Acquired Immunodeficiency Syndrome, popularly known as AIDS, is caused by HIV (Human Immunodeficiency Virus) which directly attacks the immune system of the body. The virus can be easily transmitted from one person to other through body fluid, blood transmitting or mucous membrane. The fluid of AIDS can be found in blood, semen, vaginal fluid, sex, injecting needle or any such thing.