Home > Encyclopedia of Children's Health > Immunodeficiency

Definition

Immunodeficiency disorders are a group of disorders in which part of the immune system is missing or defective. The body's ability to fight infections is, therefore, impaired. As a result, a child with an immunodeficiency disorder has frequent infections that are generally more severe and last longer than in a healthy child.

Description

The immune system is the body's main defense against infections. Any defect in the immune system decreases a person's ability to fight infections. A person with an immunodeficiency disorder may get more frequent infections, heal more slowly, and have a higher incidence of some cancers.

The normal immune system involves a complex interaction of certain types of cells that can recognize and attack foreign invaders, such as bacteria, viruses,...