Your sense of smell contributes to flavor, appetite, safety, and quality of life. Smell disorders can cause your sense of smell to become reduced or completely absent. Some people may also notice that familiar smells become distorted or experience smells that are not actually present.
What can cause smell loss?
Smell loss can have many possible causes. Some are common, while others are much less common.
- Viral infections, including the common cold.
- Chronic sinusitis, with or without nasal polyps.
- Nasal allergies.
- Head injury.
- Previous nose, sinus, or skull base surgery.
- Growths or tumors affecting the nose, sinuses, or brain.
- Certain neurologic or medical conditions.
- Smell disorders present from birth.
- Sometimes, no clear cause is identified.
The likely cause often depends on how the smell loss started, how long it has been present, and whether you have other symptoms.
How is smell loss evaluated?
Your history
We will discuss when the change started, whether it was sudden or gradual, and whether you have associated symptoms such as nasal blockage, sinus problems, allergies, a recent viral infection, head injury, or previous surgery.
Nasal endoscopy
A small endoscope allows us to examine the inside of the nose and the area through which odors reach the smell receptors. This can identify inflammation, polyps, scar tissue, growths, or other blockage.
Smell testing
Formal smell testing can help measure the degree of smell loss and provide a baseline to monitor recovery.
Imaging when needed
A CT scan or MRI may be recommended depending on your symptoms and suspected cause. Not everyone with smell loss needs imaging.
Blood tests are not routinely needed for everyone with smell loss. They may be recommended when your history suggests a specific medical or nutritional cause.
Ways to Regain Your Sense of Smell
Treatment depends on the underlying cause and may include:
- Treating nasal or sinus inflammation, including allergies, chronic sinusitis, or nasal polyps.
- Nasal steroid treatment when appropriate.
- Saline nasal irrigation when nasal or sinus inflammation is contributing.
- Smell training.
- Certain supplements, such as omega-3, in selected situations.
- In-office platelet-rich plasma (PRP) treatment for selected patients with persistent smell loss. Early research is encouraging, but this remains an evolving treatment.
Smell Training
Smell training is a simple form of rehabilitation that involves repeatedly smelling several familiar scents.
Floral
Rose, jasmine, lavender, geranium, orange blossom.
Citrus / Fruity
Lemon, orange, grapefruit, mandarin, bergamot.
Fresh / Herbal
Eucalyptus, peppermint, rosemary, pine.
Spicy
Clove, cinnamon, cardamom, nutmeg, anise.
Choose one scent from each group. The traditional combination is rose, lemon, eucalyptus, and clove, but other clearly different familiar scents can also be used.
- Smell each scent twice a day.
- Spend a few moments focusing on each scent and remembering what it should smell like.
- Continue for at least 3–4 months.
- Continue longer if you are noticing gradual improvement.
- Consistency is more important than using a specific commercial kit.
For a more detailed step-by-step guide, see Smell Retraining Therapy.
Living Safely with Smell Loss
If your sense of smell is significantly reduced or absent:
- Keep working smoke detectors in your home.
- Consider a gas-leak detector if your home uses natural gas or propane.
- Do not rely on smell alone to determine whether food has spoiled.
- Check expiry dates and label stored food when needed.
Eating, Mood & Daily Life
Smell loss can affect flavor, appetite, weight, enjoyment of food, mood, and social life. Speak with your doctor if these changes are significantly affecting your eating or quality of life.
Frequently Asked Questions
Can my sense of smell come back?
Yes. Recovery depends on the underlying cause and how long the smell loss has been present. Improvement can continue for months or even longer.
How long should I do smell training?
Aim for at least 3–4 months. You can continue longer, particularly if you are noticing gradual improvement.
Do I need to use rose, lemon, eucalyptus, and clove?
No. These are the traditional smell-training scents, but other familiar and clearly different scents can also be used.
Why does food taste different when I lose my sense of smell?
Much of what we experience as flavor comes from smell. Your ability to detect basic tastes such as sweet, salty, sour, and bitter may remain normal even though food seems bland or different.
Why do familiar smells suddenly smell unpleasant or burnt?
This is called parosmia. Familiar foods, perfumes, or other smells may temporarily smell distorted, burnt, foul, or simply different.
What if I smell something that nobody else can smell?
This is called phantosmia, where you perceive an odor even though there is no external source. Persistent phantosmia may require further evaluation.
Will I need a scan?
Not necessarily. A CT scan or MRI may be recommended depending on your symptoms, examination, and suspected cause.