• Absence of the sense of smell.
  CRISP Thesaurus
  National Institutes of Health, 2006
• An inability to perceive odors. This is a general term describing inability to smell arising in any part of the process of smelling from absorption of odorants into the nasal mucous overlying the olfactory epithelium, diffusion to the cilia, binding to olfactory receptor sites, generation of action potentials in olfactory neurons, and perception of a smell.
  Human Phenotype Ontology (HPO)
  The Human Phenotype Ontology Project, 2025
• Complete or severe loss of the subjective sense of smell. Loss of smell may be caused by many factors such as a cold, allergy, OLFACTORY NERVE DISEASES, viral RESPIRATORY TRACT INFECTIONS (e.g., COVID-19), aging and various neurological disorders (e.g., ALZHEIMER DISEASE).
  NLM Medical Subject Headings
  U.S. National Library of Medicine, 2025
• A disorder characterized by a change in the sense of smell.
  Common Terminology Criteria for Adverse Events
  U.S. National Institutes of Health, 2021
• Anosmia is complete loss of smell. Hyposmia is partial loss of smell. If unilateral, anosmia is often unrecognized.
  Merck Manuals
  Merck & Co., Inc., 2025