Which term describes an exaggerated response by the body to foreign agents?

Hypersensitivity is the term that refers to an exaggerated response by the body to foreign agents, often resulting from an overactive immune system. This can lead to various allergic reactions when the immune system identifies a harmless substance, such as pollen, food, or medications, as a threat. In hypersensitive individuals, the immune response can be so strong that it can cause significant tissue damage or adverse health effects.

This concept is important in understanding how allergies and autoimmune diseases can manifest, as they can arise from this heightened sensitivity. Additionally, distinguishing this term from others such as tolerance, which refers to the body's ability to accept foreign substances without an immune response, helps clarify the nature of immune responses in different contexts.