International Rhinologic Society Rhinology 0300-0729 61 31 2023 10 1 37454287 Position paper on olfactory dysfunction: 2023 1 110 EN K.L. Whitcroft Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany; and UCL Ear Institute, Faculty of Brain Sciences, University College London, London, UK; and The Centre for Olfactory Research and Applications, Institute of Philosophy, School of Advanced Studies, University of London, London, UK A. Altundag Department of Otorhinolaryngology, Istanbul Surgery Hospital, Istanbul, Turkey P. Balungwe Faculté de Médecine, Université Catholique de Bukavu, Bukavu, Democratic Republic of the Congo; and Hôpital Provincial Général de Référence de Bukavu, Bukavu, Democratic Republic of the Congo P. Boscolo-Rizzo Department of Medical, Surgical and Health Sciences, Section of Otolaryngology, University of Trieste, Trieste, Italy R. Douglas Department of Otorhinolaryngology, University of Auckland, New Zealand M.L.B. Enecilla Department of Otorhinolaryngology-Head and Neck Surgery, St. Luke's Medical Center, Global City, Philippines; and Department of Otolaryngology â€" Head and Neck Surgery, Asian Hospital and Medical Center, Muntinlupa, Philippines; and Department of Otorhinolaryngology, Medical Center Taguig, Taguig, Philippines A.W. Fjaeldstad The Centre for Olfactory Research and Applications, Institute of Philosophy, School of Advanced Studies, University of London, London, UK; and Department of Otorhinolaryngology, University Clinic for Flavour, Balance and Sleep, Regional Hospital Gødstrup, Herning, Denmark; and Department of Clinical Medicine, Flavour Institute, Aarhus University, Aarhus, Denmark; and Center for Eudaimonia and Human Flourishing, Linacre College, University of Oxford, Oxford, UK M.A. Fornazieri Department of Clinical Surgery, Universidade Estadual de Londrina and Pontifícia Universidade Católica do Paraná, Londrina, Brazil J. Frasnelli Research Chair in Chemosensory Neuroanatomy, Department of Anatomy, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada; and Centre for Advanced Research in Sleep Medicine, Hôpital du Sacré-Coeur de Montréal, Montréal, QC, Canada S. Gane The Centre for Olfactory Research and Applications, Institute of Philosophy, School of Advanced Studies, University of London, London, UK; and Royal National Throat Nose and Ear Hospital, UCLH, London H. Gudziol Department of Otorhinolaryngology, University of Jena, Jena, Germany N. Gupta Department of Otorhinolaryngology, University College of Medical Sciences and GTB Hospital, Delhi, India A. Haehner Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany A.K. Hernandez Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany; and Department of Otolaryngology â€" Head and Neck Surgery, Asian Hospital and Medical Center, Muntinlupa, Philippines; and Department of Otolaryngology â€" Head and Neck Surgery, Philippine General Hospital, University of the Philippines â€" Manila, Manila, Philippines E.H. Holbrook Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, USA C. Hopkins Guys and St Thomas NHS Trust, London, United Kingdom J.W. Hsieh Rhinology-Olfactology Unit, Department of Otorhinolaryngology-Head and Neck Surgery, University Hospital of Geneva Medical School, Geneva, Switzerland C. Huart Department of Otorhinolaryngology, Cliniques universitaires Saint-Luc, Brussels, Belgium; and Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium S. Husain Department of Otorhinolaryngology-Head and Neck Surgery, Faculty of Medicine, National University of Malaysia, Kuala Lumpur, Malaysia R. Kamel Department of Otorhinolaryngology, Cairo University, Cairo, Egypt J.K. Kim Department of Otorhinolaryngology-Head and Neck Surgery, Konkuk University, College of Medicine, Seoul, Republic of Korea M. Kobayashi Department of Otorhinolaryngology-Head and Neck Surgery, Mie University Graduate School of Medicine, Tsu, Mie, Japan I. Konstantinidis Smell and Taste Clinic, Second Academic Otorhinolaryngology Department, Papageorgiou Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece B.N. Landis Rhinology-Olfactology Unit, Department of Otorhinolaryngology-Head and Neck Surgery, University Hospital of Geneva Medical School, Geneva, Switzerland M. Lechner Division of Surgery and Interventional Science, University College London, London, UK; and UCL Cancer Institute, University College London, London, UK; and ENT Department, Homerton Healthcare NHS Foundation Trust, London, UK A. Macchi ENT Clinic, University of Insubria, ASST Sette Laghi, Varese, Italy P.P. Mazal Servicio de Otorrinolaringología, Hospital Italiano de Buenos Aires, Buenos Aires, Argentina I. Miri Service Médecine Physique Réadaptation fonctionnelle, Institut Mohamed Kassab d'Orthopédie, Mannouba, Tunisia T. Miwa Department of Otorhinolaryngology, Kanazawa Medical University, Uchinada, Kahoku, Ishikawa, Japan E. Mori Department of Otorhinolaryngology, Jikei University, School of Medicine, Tokyo, Japan J. Mullol Rhinology Unit and Smell Clinic, ENT Department, Hospital Clínic, Universitat de Barcelona; IDIBAPS; CIBERES. Barcelona, Catalonia, Spain C.A. Mueller Department of Otorhinolaryngology, Medical University of Vienna, Vienna, Austria G. Ottaviano Department of Neurosciences DNS, Otolaryngology Section, University, Padua, Italy Z.M. Patel Department of Otolaryngology, Stanford University School of Medicine, Stanford, California, USA C. Philpott Norwich Medical School, University of East Anglia, Norwich, UK; and The Smell and Taste Clinic, James Paget University Hospital, Gorleston, UK J.M. Pinto Section of Otolaryngology-Head and Neck Surgery, The University of Chicago Medicine and Biological Sciences, Chicago, IL, USA V.R. Ramakrishnan Department of Otolaryngology-Head and Neck Surgery, Indiana University of School Medicine, Indianapolis, IN, USA Y. Roth The Institute for Nose and Sinus Therapy and Clinical Investigations, Department of Otolaryngology - Head and Neck Surgery, Edith Wolfson Medical Center, Tel Aviv University Sackler Faculty of Medicine, Holon, Israel R.J. Schlosser Department of Otolaryngology â€" Head and Neck Surgery, Medical University of South Carolina, Charleston, SC, USA P. Stjärne Section of Rhinology, Department of Otorhinolaryngology, Karolinska University Hospital and Karolinska Institute, Stockholm, Sweden L. Van Gerven Department of Otorhinolaryngology, UZ Leuven, Belgium; and Department of Neurosciences, Experimental Otorhinolaryngology, KU Leuven, Belgium; and Department of Microbiology, Immunology and Transplantation, Allergy and Clinical Immunology Research Unit, KU Leuven, Belgium J. Vodicka Department of Otorhinolaryngology and Head and Neck Surgery, Hospital Pardubice, Faculty of Health Studies, University of Pardubice, Pardubice, Czech Republic A. Welge-Luessen University Hospital Basel - Otorhinolaryngology, Basel, Switzerland P.J. Wormald Department of Surgeryâ€"Otorhinolaryngology Head and Neck Surgery, University of Adelaide, Adelaide, SA, Australia T. Hummel Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany 3097 10.4193/Rhin22.483 Background: Since publication of the original Position Paper on Olfactory Dysfunction in 2017 (PPOD-17), the personal and societal burden of olfactory disorders has come sharply into focus through the lens of the COVID-19 pandemic. Clinicians, scientists and the public are now more aware of the importance of olfaction, and the impact of its dysfunction on quality of life, nutrition, social relationships and mental health. Accordingly, new basic, translational and clinical research has resulted in significant progress since the PPOD-17. In this updated document, we present and discuss currently available evidence for the diagnosis and management of olfactory dysfunction. Major updates to the current version include, amongst others: new recommendations on olfactory related terminology; new imaging recommendations; new sections on qualitative OD and COVID-19 OD; updated management section. Recommendations were agreed by all co-authors using a modified Delphi process. Conclusions: We have provided an overview of current evidence and expert-agreed recommendations for the definition, investigation, and management of OD. As for our original Position Paper, we hope that this updated document will encourage clinicians and researchers to adopt a common language, and in so doing, increase the methodological quality, consistency, and generalisability of work in this field.