Our Health Library information does not replace the advice of a doctor. Please be advised that this information is made available to assist our patients to learn more about their health. Our providers may not see and/or treat all topics found herein.

Immune system

The immune system is the body's natural defense system that helps fight infections. The immune system is made up of antibodies, white blood cells, and other chemicals and proteins that attack and destroy substances such as bacteria and viruses that they recognize as foreign and different from the body's normal healthy tissues.

The immune system is also responsible for allergic reactions and allergies, which may occur when the immune system incorrectly identifies a substance (allergen), such as pollen, mold, chemicals, plants, and medicines, as harmful.

Sometimes the immune system also mistakenly attacks the body's own cells, which is known as an autoimmune disease.

Current as of: September 25, 2023

Author: Ignite Healthwise, LLC Staff

Clinical Review Board
All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.