Primary immunodeficiency disorders also called primary immune disorders or primary immunodeficiency weaken the immune system, allowing infections and other health problems to occur more easily. Many people with primary immunodeficiency are born missing some of the body immune defenses, which leaves them more susceptible to germs that can cause infections. Some forms of primary immunodeficiency are so mild they may go unnoticed for years. Other types are severe enough that they are discovered almost as soon as an affected baby is born. Treatments can boost the immune system for many types of primary immunodeficiency disorders. Most people with the condition lead relatively normal, productive lives. Researchers have identified more than 150 different types of primary immunodeficiency disease (also known as primary immune deficiency disease).