The impact of olfactory loss on quality of life: a 2025 review

Abstract

For a long time, the sense of smell was considered the neglected stepbrother of human sensory abilities, and the loss of smell has received little attention. This perception changed dramatically with the COVID-19 pandemic, which led to millions of people losing their sense of smell, and some never recovering. COVID-19 not only increased general awareness of olfactory disorders but also accelerated research into the role of smell in nonverbal communication and mental health. This review aims to summarize the literature on the impact of olfactory disorders on quality of life. Starting from the functions of olfaction in healthy individuals, we will briefly describe the most common olfactory disorders and their effect on an individual's life, including nutrition and eating behaviors, social and psychological well-being, and exposure to environmental hazards. Consequences of olfactory loss permeate many spheres of daily life. On average, dysosmia has a moderate impact on quality of life, though for some patients the effects can be severe.

Keywords: anosmia; coping strategies; mental health; olfaction; olfactory loss.

Fig. 1.

Causes and types of olfactory impairment.

Fig. 2.

Forest plot of the effects of olfactory loss on the aspects of quality of life. The selection of studies for Fig. 2 was based on the following criteria: (1) published after 2014, (2) presenting a cross-sectional comparison of dysosmic (anosmic, hyposmic, or both) and healthy controls in the respected area impacted by the smell loss or longitudinal data for dysosmia, and (3) available descriptive data to calculate Cohen’s d effect size. Thus, the presented selection is not a systematic review or meta-analysis. Despite Kamarava (2021) study being an outlier, we decided not to exclude it from the Figure. Smd—Standardized mean difference (Cohen’s d), N—total number of participants for the study, QoL—quality of life. Horizontal blue lines depict 95% confidence interval for the effect sizes marked with red squares. Study weight is proportional to study precision, specifically the span of the standard error of the estimate of a study. For Pence et al. 2014 no confidence interval data is reported.