First Time User? Enroll now.
As the COVID-19 situation has evolved, our visitor policy is evolving as well. Get full details.
For the most current information, please visit our Coronavirus resource pages.
Home > Health Library > Antibodies
Antibodies are proteins made by the body's natural defense system (immune system) to fight foreign substances, such as bacteria. Antibodies attach themselves to the foreign substance, allowing other immune system cells to attack and destroy the substance.
The surfaces of viruses, fungi, and bacteria contain markers called antigens. To destroy the viruses, fungi, or bacteria, the immune system creates antibodies that are specific for each antigen.
Blood tests can detect antibodies to certain bacteria, fungi, and viruses, such as the viruses that cause chickenpox, HIV infection, hepatitis, and mononucleosis. Some conditions can be diagnosed by detecting antibodies in a person's blood to the virus, fungus, or bacteria that is causing the condition.
Sometimes the body responds to its own tissue as though the tissue was a foreign substance, creating antibodies against the tissue and triggering reactions that cause normal cells to be destroyed. This is called an autoimmune response or autoimmune disease.
Current as of: June 17, 2021
Author: Healthwise Staff
Medical Review:E. Gregory Thompson MD - Internal Medicine & Adam Husney MD - Family Medicine & Martin J. Gabica MD - Family Medicine
To learn more about Healthwise, visit Healthwise.org.
© 1995-2021 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.
Feeling under the weather?
Use our interactive symptom checker to evaluate your symptoms and determine appropriate action or treatment.
Get started learning more about your health!
Our Interactive Tools can help you make smart decisions for a healthier life. You'll find personal calculators and tools for health and fitness, lifestyle checkups, and pregnancy.