Health Dictionary
Reliable, easy-to-read patient information on common medical conditions — written in plain language, free of jargon, and grounded in current evidence. Browse the most frequent diagnoses, understand what they mean for everyday life, and learn which steps and questions help you have a focused conversation with your doctor.
Anosmia
Introduction
Synonyms and keywords: Lack of functioning olfaction, inability to perceive odors.
Overview
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Overview
Anosmia is the inability to perceive odor, or in other words a lack of functioning olfaction.
Causes
A temporary loss of smell can be caused by a stuffy nose or infection. In contrast, a permanent loss of smell may be caused by death of olfactory receptor neurons in the nose, or by brain injury in which there is damage to the olfactory nerve or damage to brain areas that process smell (see olfactory system). The lack of the sense of smell at birth, usually due to genetic factors, is referred as congenital anosmia. Anosmia may very occasionally be an early sign of degenerative brain diseases such as Parkinson’s disease and Alzheimer’s disease.
Epidemiology and Demographics
In the United States, more than 2 million people suffer from anosmia.
References
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Causes
Overview
A temporary loss of smell can be caused by a stuffy nose or infection. In contrast, a permanent loss of smell may be caused by death of olfactory receptor neurons in the nose, or by brain injury in which there is damage to the olfactory nerve or damage to brain areas that process smell (see olfactory system). The lack of the sense of smell at birth, usually due to genetic factors, is referred as congenital anosmia. Anosmia may very occasionally be an early sign of degenerative brain diseases such as Parkinson’s disease and Alzheimer’s disease.
Causes
Common Causes
- Allergies
- Common cold
- Infection
- Nasal polyp
- Old age
- Sinusitis
- Stuffy nose
- Trauma
Causes by Organ System
| Cardiovascular | No underlying causes |
| Chemical / poisoning | Acrylates, Cadmium poisoning, Methacrylates |
| Dermatologic | No underlying causes |
| Drug Side Effect | No underlying causes |
| Ear Nose Throat | Common cold, Ethmoid bone injuries, Nasal polyp, Samter’s triad, Sinusitis, Stuffy nose, Swollen turbinate, Upper respiratory tract infection, Allergic and viral rhinitis |
| Endocrine | Kallmann syndrome, Diabetes mellitus |
| Environmental | Nasal spray, Smoking, Zinc deficiency |
| Gastroenterologic | Cystic fibrosis |
| Genetic | Anosmin-1 absence, Anosmin-1 damage, Bardet-Biedl syndrome, Cystic Fibrosis, Genetic factors, Intersexuality, KAL1 gene deletion, KAL1 gene mutation, Kallmann syndrome, Male pseudohermaphroditism, Down’s syndrome |
| Hematologic | No underlying causes |
| Iatrogenic | Permanent tracheostomy, Nasal spray |
| Infectious Disease | Infection, Primary amoebic meningoencephalitis, Sinusitis, Upper respiratory tract infection, Herpes virus infection, Human immunodeficiency virus infection |
| Musculoskeletal / Ortho | Paget’s disease with facial, maxillomandibular involvement |
| Neurologic | Alzheimer’s disease, Brain injury, Degenerative brain diseases, Dementia with Lewy bodies, Esthesioneuroblastoma, Ethmoid bone injuries, Holoprosencephaly, Parkinson’s disease, Primary amoebic meningoencephalitis, Huntington’s chorea, Shy-Drager syndrome, Temporal lobectomy, Olfactory neuroblastoma and meningioma |
| Nutritional / Metabolic | No underlying causes |
| Obstetric/Gynecologic | No underlying causes |
| Oncologic | No underlying causes |
| Opthalmologic | No underlying causes |
| Overdose / Toxicity | Toxins, Zinc gluconate |
| Psychiatric | Korsakoff’s psychosis, Schizophrenia |
| Pulmonary | Cystic fibrosis, Samter’s triad, Influenza |
| Renal / Electrolyte | Hemodialysis |
| Rheum / Immune / Allergy | Allergies, Samter’s triad, Sjögren’s syndrome |
| Sexual | No underlying causes |
| Trauma | Ethmoid bone injuries, Head trauma, Trauma |
| Urologic | No underlying causes |
| Dental | No underlying causes |
| Miscellaneous | Old age |
Causes in Alphabetical Order
- Alzheimer’s disease
- Acrylates
- Allergies
- Anosmin-1 absence
- Anosmin-1 damage
- Bardet-Biedl syndrome
- Brain injury
- Cadmium poisoning
- Common cold
- Cystic Fibrosis
- Degenerative brain diseases
- Dementia with Lewy bodies
- Esthesioneuroblastoma
- Ethmoid bone injuries
- Genetic factors
- Head trauma
- Holoprosencephaly
- Infection
- Intersexuality
- KAL1 gene deletion
- Kallmann syndrome
- Male pseudohermaphroditism
- Methacrylates
- Nasal polyp
- Nasal spray
- Old age
- Parkinson’s disease
- Permanent tracheostomy
- Primary amoebic meningoencephalitis
- Samter’s triad
- Sinusitis
- Smoking
- Stuffy nose
- Swollen turbinate
- Toxins
- Trauma
- Upper respiratory tract infection
- Zinc deficiency
- Zinc gluconate
References
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Hilda Mahmoudi M.D., M.P.H.[2]
Differentiating Anosmia from other Diseases
- Hyposmia – Reduced perception of smell
- Parosmia – Altered perception of smell
- Phantosmia – Perception of nonexistent smell
References
Epidemiology and demgraphics
Please help WikiDoc by adding more content here. It’s easy! Click here to learn about editing.
Overview
In the United States, more than 2 million people suffer from anosmia.
References
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Diagnosis
Diagnosis
History and Symptoms | Physical Examination | Laboratory Findings | CT | MRI | Other Diagnostics Studies
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Ekata Anthonia Abhulimen, M.D.[2]