Immune disorders occur when a human body’s immune system does not function in the way it should. Immune disorders may be broadly categorized on the basis of the components of the affected immune system, the extent to which the immune system is overactive or underactive and whether the immune disorder itself is acquired or is a congenital disorder. Primary immunodeficiency diseases or PIDs are those types of immune disorders that are the result of inherited genetic conditions. Over 150 primary immunodeficiency diseases have been identified by medical science. These include pneumonia, skin infections, ear infections and so on. Apart from PIDs, secondary or acquired immune deficiencies are caused by virus or some types of immune suppressing drugs. The deadly AIDS is an example of an acquired immune deficiency disease. Hide this