What medical term describes inflammation?

The term that describes inflammation is "itis." In medical terminology, the suffix "itis" is commonly added to the root of a word to indicate an inflammatory condition related to a specific organ or tissue. For example, "appendicitis" refers to inflammation of the appendix, while "arthritis" signifies inflammation of the joints. This suffix helps healthcare professionals understand the nature of the condition quickly and accurately.

The other options represent different concepts: "infection" refers to the invasion and multiplication of pathogens like bacteria or viruses in the body, "infestation" indicates the presence of larger parasites, such as insects, in or on a host, and "Isis" does not have a relevant medical meaning. Thus, "itis" is the most appropriate and direct term associated specifically with inflammation.