From the Guidelines
The medical term for a decreased sense of smell is hyposmia. This condition represents a partial loss of smell ability, as opposed to anosmia, which is a complete loss of smell 1. Hyposmia can be temporary or permanent and may result from various causes including upper respiratory infections, nasal polyps, allergies, head trauma, certain medications, aging, or neurodegenerative diseases like Parkinson's or Alzheimer's.
Causes and Diagnosis
- Upper respiratory infections
- Nasal polyps
- Allergies
- Head trauma
- Certain medications
- Aging
- Neurodegenerative diseases According to the european position paper on rhinosinusitis and nasal polyps 2020 1, smell impairment is a symptom which differentially affects CRS patients in terms of severity of smell disorder.
Treatment
Treatment depends on the underlying cause - for instance, if related to allergies, antihistamines or nasal steroids might help; if caused by nasal polyps, surgical removal might be necessary 1. For viral-induced hyposmia, smell training therapy can be beneficial, which involves repeatedly smelling strong scents like essential oils (lemon, rose, clove, and eucalyptus) for short periods daily to help retrain the olfactory system 1.
Importance of Medical Evaluation
If you experience a sudden decrease in smell, especially if accompanied by other symptoms, it's essential to consult a healthcare provider for proper diagnosis and treatment, as it could indicate an underlying condition requiring medical attention 1.
From the Research
Definition of Decreased Sense of Smell
- The term for a decreased sense of smell is hyposmia 2, 3, 4, 5.
- Hyposmia is often accompanied by anosmia, which is the complete loss of smell 2, 3, 4, 5.
Causes of Hyposmia
- Hyposmia can be caused by various factors, including chronic sinonasal diseases, severe head trauma, upper respiratory infections, and neurodegenerative diseases 2.
- It can also be caused by viral infections such as rhinovirus and SARS-CoV-2 3, 5.
- Trauma, inflammatory conditions, and neoplasms are also potential causes of hyposmia 3, 5.
Effects of Hyposmia
- Hyposmia can significantly affect a patient's quality of life, impairing their ability to sense warning odors in foods and the environment, and hindering social interactions, eating, and feelings of well-being 2.
- It can also influence food intake and lead to increased salt usage in some patients, as they try to compensate for flavor loss 6.
Diagnosis and Treatment of Hyposmia
- The diagnosis of hyposmia typically involves a thorough history and physical, as well as validated orthonasal smell tests such as the Sniffin' Sticks and the UPSIT 5.
- Treatment options for hyposmia include intranasal corticosteroids and olfactory training, which have shown promise in improving olfactory function 3, 4.