Purpose: The aim of this article is to provide a summary of findings concerning olfactory loss associated with pathological neurodegenerative changes which occur over the course of Alzheimer’s disease.

Views: It is shown that compared with the healthy population, olfactory dysfunction is more pronounced in neurodegenerative diseases and precedes symptoms typical of those diseases. One of the primary differences between physiological, age-associated and pathological olfactory loss is the patients’ awareness of the deficit. Healthy hyposmic or even anosmic patients are often aware of the problems caused by this dysfunction; however, it is not the case for patients in the preclinical, prodromal or clinical stages of Alzheimer’s disease.

Conclusions: The clinical value of olfactory function assessments should be emphasized, as it may provide information about the potential prodromal symptoms of Alzheimer’s disease.