Immune System and Allergy Terms

Immune cells, immune responses, allergies, vaccines, and immunologic conditions. Browse definitions and meanings below.

264 terms

What is immunology?

Immunology is the study of how the body defends itself, and of what happens when that defense misfires. It covers recognition of invaders, the response mounted against them, the memory that makes a second encounter faster, and the restraint that stops the response turning on the body itself.

An allergy is that system reacting vigorously to something harmless, such as pollen or a food protein. An autoimmune condition is the same machinery aimed at the body's own tissue. Immunodeficiency is too little response rather than too much. Three very different problems, one shared vocabulary.

Terms in this topic

Alphabetical order

For learning, not diagnosis. This glossary provides general educational information and is not a substitute for advice from a qualified healthcare professional. If you may be experiencing a medical emergency, contact local emergency services.