Abstract

Topicality: Definitions provide shared knowledge and a common understanding of a topic. Agreed terminology is essential for communication and interconnected activities. This is important when we talk, write, or read about science. By providing either an unambiguous description of the phenomenon or a reasonable interpretation of its underlying causes, each definition should allow for the clear identification and classification of referent objects. Current terms describing olfactory dysfunction are vague and overlapping.

Objective: In order to clearly and unambiguously define and interpret the most common terms related to smell, namely: dysosmia, anosmia, hyposmia, normosmia, hyperosmia, olfactory intolerance, parosmia, and phantosmia (also known as “olfactory hallucination”), we wrote this article for Ukrainian doctors and scientists. This will allow authors and readers of olfaction-related literature to have a common understanding of what is meant when these terms are used.

Results: Quantitative olfactory function is often associated with terms related to quantitative olfactory dysfunction (i.e., “anosmia,” “hyposmia,” and “normosmia”). The word “subjective” refers to a person’s self-assessment of olfactory function. Qualitative olfactory dysfunction (i.e., parosmia, phantosmia) is often considered “subjective,” given that validated psychophysical tests to assess these conditions are currently unavailable. However, the word “subjective” can also be added to quantitative terms (i.e., anosmia, hyposmia, or normosmia) to denote a self-reported olfactory function or dysfunction that is not confirmed by psychophysical olfactory testing. Although measured olfactory function is often the basis for treatment of patients with olfactory complaints, subjective olfactory function may sometimes better reflect quality of life.

Conclusions: We propose standardizing the use of the terms “dysosmia”, “anosmia”, “hyposmia”, “normosmia”, “hyperosmia”, “olfactory intolerance”, “parosmia” and “phantosmia” or “olfactory hallucinations” in communication related to smell. Further clarification of whether olfactory function is “measured” or “subjective” is useful in clinical settings. The precise use of these terms will improve scientific communication in a field that is poised to continue to evolve.

Keywords: dysosmia, anosmia, hyposmia, normosmia, hyperosmia, olfactory intolerance, parosmia, phantosmia, cacosmia, olfactory tests.