AIDS (Acquired immune deficiency syndrome) is the diseases which weakens the immune system of the body. It is caused by a virus called HIV (Human immunodeficiency virus). When this virus enters the blood streams, a person may become infected with it & is said to be HIV positive.
In HIV infection, the virus damages the immune system. Therefore, the body is not able to fight minor infections such as cold and cough. In such cases, a minor cold can become pneumonia. Similarly, a minor gut infection can lead to diarrhoea. Thus, these minor infections can kill an HIV-AIDS patient.
It is a type of infectious disease.