Loss of smell (anosmia): Causes and how an ENT specialist can help
Losing your sense of smell can be concerning. Beyond affecting your ability to enjoy food and familiar scents, it can also make it harder to detect potential dangers such as smoke or spoiled food.
For some people, the change occurs suddenly following a cold or viral infection. For others, their sense of smell may gradually weaken or disappear over time.
Read on to understand the causes of smell loss and how the condition is diagnosed and treated at an ENT and sinus clinic.
Understanding Anosmia
The medical term for a complete loss of smell is anosmia, while a reduced sense of smell is known as hyposmia. Both can have a number of causes, including nasal inflammation, viral infections and sinus conditions.
If you notice a change in your sense of smell, identifying the underlying cause is important in determining the most appropriate treatment.
What causes a loss of sense of smell?
Your ability to smell depends on odour molecules reaching specialised sensory cells high inside your nose.
These cells then send signals to the brain, where smells are recognised and interpreted. If airflow is blocked or the sensory pathway is impacted, your ability to smell can change.
Some of the common causes of loss of smell include:
- Viral infections: Colds, flu, and COVID-19 can temporarily or sometimes persistently impact smell.
- Sinusitis: Inflammation in the nasal passages and sinuses can interfere with your ability to smell properly.
- Allergic rhinitis: Nasal swelling, congestion and excess mucus can make it harder for smells to reach the receptors.
- Head injuries: Trauma can damage the nerves.
- Nasal polyps: Obstruction of airflow.
- Other factors: Ageing, medication, and some neurological conditions.
What other symptoms may occur with anosmia?
Loss of smell may appear alongside nasal congestion, a runny nose, facial pressure, an itchy nose, or sneezing. You may also find that some foods taste less bland or less enjoyable.
Your sense of smell plays an important role in how you experience taste. When your sense of smell is reduced, food may taste different or less enjoyable, even though your basic sense of taste remains intact. You may also find it harder to detect spoiled food.
When should you see an ENT specialist for loss of smell?
A temporary change when you have a cold may improve as the infection gets better. However, you should arrange a medical assessment if your sense of smell doesn’t come back, if it’s getting worse, or if it just disappears suddenly.
An ENT specialist can also assess persistent congestion, recurring sinus symptoms, and things like suspected nasal polyps.
If your loss of smell occurs after you have suffered a head injury, you should seek urgent medical attention straight away. This is especially important if you have any other concerning symptoms such as facial drooping, difficulty speaking, confusion or a severe headache.
How is a loss sense of smell diagnosed?
An ENT specialist will discuss your symptoms, including when they began, whether they developed following an injury or infection, and whether you have any allergies, changes in taste or nasal blockages.
An assessment could include any of the following:
- Nasal examination to look for swelling, visible abnormalities, or discharge.
- Smell testing: Tests that help understand your ability to detect certain odours.
- Nasal endoscopy: A thin scope with a camera to look inside your nasal passages.
- Further investigations: Imaging and other tests may be required depending on results.
Not everyone will require all of these tests. The investigations needed will depend on your symptoms and the findings from the initial examination.
What does loss of smell treatment involve?
Treatment for loss of smell depends on the underlying cause, how long the condition has persisted and whether the sensory pathway has been affected.
One common approach is treating nasal inflammation:
Medications such as nasal corticosteroid sprays may help improve symptoms when allergies or sinus inflammation are contributing factors.
Smell training may also be beneficial for some patients. This involves regularly smelling selected scents as part of a structured routine to help stimulate the sense of smell, particularly following a viral infection.
Another approach involves managing underlying sinus conditions. Medical treatment for sinusitis or nasal polyps may help restore the sense of smell in some patients. However, surgery may be considered if significant nasal obstruction persists despite medication.
Treatment generally aims to address the underlying cause. Antibiotics, for example, are only prescribed when there is a specific clinical indication, as they are not routinely required for smell loss.
Recovery varies from person to person. Some regain their sense of smell relatively quickly, while others experience gradual improvement or persistent changes.
Follow-up care may be recommended depending on the underlying condition and response to treatment.
Speak to a specialist
Concerned about a loss of smell or your general nasal health? Our ENT doctor can assess your symptoms, identify potential underlying causes and recommend appropriate treatment options tailored to your needs.
Get in touch with us to arrange a consultation and take the first step towards finding relief
Dr. Ong Yew Kwang
Senior Consultant ENT Specialist & Rhinologist
Dr Ong Yew Kwang is an experienced ENT specialist with over 20 years of clinical practice. He graduated with honours from Trinity College, University of Dublin and completed ENT specialist training in 2008, earning the gold medal in the national exit examination. He later undertook subspecialty fellowship training in Rhinology and Endoscopic Skull Base Surgery at the University of Pittsburgh Medical Center, USA.
Before entering private practice, Dr Ong served as Senior Consultant and Director of Clinical Service at the National University Hospital (NUH), where he co-led the endoscopic skull base programme. He also holds a Master of Medicine in Sleep Medicine and a Post-Graduate Certificate in Allergy.