Loss of smell: symptoms, treatment, and when to worry
Last updated September 3, 2026.
Losing your sense of smell is common, and the usual suspects are colds, sinus problems, nasal polyps, and allergies rather than anything sinister. It can be a total loss (anosmia) or a partial or distorted sense where familiar things smell wrong. Most cases improve once the nose is treated, though recovery can take months.
What causes it?
Smell depends on air reaching a patch of nerve cells high inside the nose, and on those nerves working. Anything that blocks airflow, like a cold, sinusitis, polyps, or allergy swelling, dulls smell. Viruses, including COVID-19, can also damage the smell nerves directly, which is why smell can stay off after the congestion clears. Less common causes include head injury, some medicines, ageing, and neurological conditions.
What actually helps?
- Treat the nose: salt-water rinses and, when advised, steroid nasal sprays or drops calm the inflammation blocking the smell nerves. A short course of a decongestant is for colds only, not long-term use.
- Try smell training: sniffing four familiar scents, such as rose, lemon, clove, and eucalyptus, for about 20 seconds each, twice a day, for several months, helps the smell nerves recover. It is the best-evidenced home treatment after viral loss.
- Review medicines and habits: some drugs blunt smell, and smoking damages it, so raise both at your appointment.
- Adapt for safety: fit and test smoke alarms, consider a natural gas detector, and date your food, since you cannot rely on sniffing out smoke, gas, or spoilage.
- See a doctor if it persists: loss lasting weeks, or with no obvious cold, deserves an exam and sometimes a scan or ENT referral.
When is it an emergency?
Loss of smell alone is not an emergency, but some versions are warnings. Call 911 if it comes with facial droop, arm weakness, or slurred speech, which suggests stroke. Get same-day assessment if smell vanished after a head injury, or comes with new confusion or a severe headache. A persistently blocked or bleeding nostril on one side only needs prompt ENT review. Pymander's escalation routing is built and tested specifically for this class of decision; see the safety architecture working paper.
What a Pymander AI doctor consult looks like
Illustrative example, not a real member's messages.
Common questions
Is loss of smell still a COVID symptom?
Yes, though it is less dominant in recent variants than it was early in the pandemic. Any new loss of smell alongside cold symptoms is still a reason to consider a COVID test, especially before visiting vulnerable people. The good news is that most COVID-related smell loss recovers within weeks, and the remainder often improves with smell training over the following months.
Can your sense of smell come back?
Usually, yes. Blockage-type loss returns when the nose clears. After viral nerve damage, most people recover much of their smell within weeks to months, and smell training measurably improves the odds and speed. Recovery can be messy along the way, with phases where things smell distorted or foul before they normalize. Loss lasting beyond a few months deserves an ENT assessment.
How does smell training work?
You pick four strong, familiar scents, classically rose, lemon, clove, and eucalyptus, and sniff each gently for about 20 seconds, twice a day, concentrating on what the smell should be. The repeated exposure stimulates recovery and rewiring of the smell pathways. It is done for at least three months, and the scent set can be rotated to keep the stimulation fresh.
Is losing smell an early sign of Parkinson's or dementia?
It can be an early feature of Parkinson's disease and some dementias, appearing years before other symptoms. Context matters: loss that arrived with a cold or sinus problem points to the nose, while gradual unexplained loss in an older adult, especially with movement changes or memory concerns, is worth mentioning to a doctor. It is a clue to discuss, not a diagnosis to fear alone.
Why do things smell bad or wrong since my cold?
That is parosmia, a distortion where recovering smell nerves misread signals, so coffee smells burnt or food smells foul. It commonly shows up as smell returns after viral loss and, counterintuitively, usually signals recovery in progress. Smell training helps, and identifying a few safe foods that still taste normal keeps eating bearable while it settles.
Can nasal polyps take away my sense of smell?
Yes. Polyps are soft, painless growths that block the upper nose, and a gradually fading sense of smell is often their first sign, alongside a blocked nose, reduced taste, and a runny or stuffy feeling. Steroid sprays or drops shrink most polyps, with surgery for stubborn ones. Smell often returns well once the blockage is treated.