HIV is a virus which attacks the white blood cells (called T-cells, also known as CD4 Cell and T-helper cells). These CD4 cells in blood co-ordinate the immune system to fight disease in the body. Invasion of T-cells by HIV (Human Immunodeficiency Virus), destroys CD4 cells present in human blood, making and left body without any defense system, HIV also alter the immune system and making humans more prone to infections and diseases. This worsens the health of patient as the HIV proliferates and it gave rise to a medical condition called AIDS (Acquired Immune Deficiency Syndrome) an advanced stages of HIV infection.