Causes, Diagnosis, Treatment, and Smell Training
Loss of smell, medically known as anosmia, or reduced smell (hyposmia), is a common symptom that can occur for several reasons. In many cases it is temporary, but persistent smell loss may indicate an underlying nasal or sinus condition that requires specialist evaluation.
Why Is the Sense of Smell Important?
Smell is closely connected to taste. When smell is reduced, many people notice that food tastes bland or less enjoyable.
Smell also plays an important role in safety by helping detect:
- Smoke or fire
- Gas leaks
- Spoiled food
- Environmental hazards
Because of these important functions, persistent loss of smell should not be ignored.
Common Causes of Loss of Smell
Loss of smell can result from several medical conditions.
Common causes include:
- Nasal polyps
- Chronic sinusitis
- Viral infections such as the common cold or COVID-19
- Allergic rhinitis
- Head trauma
- Aging
- Neurological disorders
Among these, chronic sinus inflammation and nasal polyps are among the most common causes seen in ENT practice.
Loss of Smell Caused by Nasal Polyps
Nasal polyps are soft inflammatory growths that develop in the lining of the nose
and sinuses.
They can cause smell loss through two mechanisms:
- Physical blockage of airflow to the olfactory region
- Inflammation that interferes with smell receptor function
Patients with nasal polyps often report progressive smell loss along with nasal congestion, postnasal drip, facial pressure, and recurrent sinus infections.
How Loss of Smell Is Diagnosed
Evaluation by an ENT specialist may include:
- Detailed medical history
- Nasal examination
- Nasal endoscopy
- CT scan of the sinuses
- Smell testing in selected cases
These investigations help determine whether smell loss is caused by nasal obstruction, sinus inflammation, or neurological factors.
Treatment Options for Loss of Smell
Treatment depends on the underlying cause.
Common treatments may include:
- Nasal corticosteroid sprays
- Saline nasal irrigation
- Allergy treatment
- Short courses of oral steroids in selected cases
- Endoscopic sinus surgery when nasal polyps are present
These treatments aim to reduce inflammation and restore airflow to the smell receptors.
Biologic Therapy and Smell Recovery
In recent years, biologic medications have become an important treatment option for patients with severe nasal polyps and persistent smell loss.
These medications target inflammatory pathways responsible for chronic sinus disease.
Examples include:
- Dupilumab
- Mepolizumab
- Tezepelumab
Clinical studies have shown that biologic therapy can significantly improve the sense of smell in selected patients.
Smell Training for Loss of Smell
Smell training is a simple and evidence-based technique that may help restore the sense of smell, especially after viral infections or inflammation.
The method involves repeatedly smelling specific scents to stimulate recovery of the olfactory nerves.
A typical smell training program includes four familiar scents:
- Rose (floral)
- Lemon (fruity)
- Clove (spicy)
- Eucalyptus (resinous)
Patients smell each scent for about 20 seconds, twice daily.
Smell training is usually continued for several months and has been shown in research studies to improve smell recovery in many patients.
This technique is safe, inexpensive, and can be combined with medical treatment.
When Should You See a Specialist?
You should seek evaluation if you experience:
- Loss of smell lasting more than 3–4 weeks
- Persistent nasal congestion
- Recurrent sinus infections
- Reduced smell affecting quality of life
Early evaluation increases the chances of successful treatment.
Expert Rhinology Care
At Dr. Tamer Fawzy’s Rhinology Clinic, patients with smell disorders receive comprehensive evaluation and personalized treatment plans.
Management may include medical therapy, sinus surgery, or advanced biologic treatments, depending on the underlying cause.
The goal is to restore nasal function, improve smell, and enhance overall quality of life.
