Immune system disorders happen when your immune system doesn't work the way it should. Your immune system is your body's defense network that fights off infections and diseases. When this system malfunctions, it can attack your own tissues, fail to respond to threats, or overreact to harmless substances.
There are three main types of immune system disorders. Autoimmune disorders occur when your immune system mistakes healthy cells for dangerous invaders and attacks them. Immunodeficiency disorders happen when parts of your immune system are missing or don't work properly, leaving you vulnerable to infections. Allergic disorders develop when your immune system overreacts to normally harmless substances like pollen or food.
These conditions range from mild to severe and can affect people of all ages. Some people are born with immune system problems, while others develop them later in life. Early detection and proper management can help many people with immune disorders live healthy, active lives.