Anosmia
Also known as: anosmia, loss of smell, olfactory dysfunction, hyposmia, reduced sense of smell, post-viral olfactory dysfunction, post-infectious smell loss, COVID-19-related smell loss, traumatic anosmia, congenital anosmia
Anosmia is the complete loss of the sense of smell, while hyposmia means reduced smell. Smell disturbance may also involve parosmia, in which familiar odours smell distorted, or phantosmia, in which an odour is perceived without an external source. Common causes include viral upper-respiratory infections, COVID-19, allergic rhinitis, chronic rhinosinusitis, nasal polyps, nasal obstruction, head injury, ageing and some medicines. Less commonly, smell loss may be associated with neurological disease, intracranial pathology, toxin exposure, congenital conditions or previous surgery. Because smell contributes substantially to flavour perception, patients may report loss of taste even when basic sweet, salty, sour, bitter and umami sensation remains intact. Assessment may include the timing and pattern of onset, nasal and neurological symptoms, recent infection, trauma, medicine and occupational exposure, nasal examination, validated smell testing and selected imaging or specialist investigations. Management targets the underlying cause. Smell training is commonly recommended for persistent post-viral smell loss and involves repeated, structured exposure to selected odours over an extended period. Patients must also address safety risks involving smoke, fire, gas leaks and spoiled food. Acupuncture and Chinese herbal medicine may be considered only as adjunctive care. Evidence is insufficient to conclude that they reliably restore olfactory nerve function or treat structural, neurological or intracranial causes. TCM patterns may include Wind-Cold obstructing the Lung, Wind-Heat attacking the Lung, Lung Qi deficiency, Spleen Qi deficiency with Phlegm-Dampness, Qi and Blood stasis obstructing the nasal orifices and Kidney essence deficiency. [1][2][3][4]
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Lifestyle & Diet
- •Seek medical assessment for sudden, unexplained, persistent or one-sided smell loss.
- •Follow treatment for allergy, sinusitis, nasal polyps or other diagnosed causes.
- •Do not stop prescribed intranasal corticosteroids or other medicines without consulting the prescriber.
- •Review medicines with a doctor or pharmacist because some medicines may alter smell.
- •Undertake structured smell training when recommended.
- •Smell training commonly uses several familiar, non-irritating odours smelled briefly and consistently over many weeks or months.
- •Do not test smell using ammonia, bleach, petrol, solvents, smoke or other hazardous chemicals.
- •Install and regularly test smoke alarms.
- •Use functioning gas, carbon-monoxide or other appropriate household alarms where relevant.
- •Consider electric appliances rather than unmonitored gas flames when smell loss is severe.
- •Label food with opening dates and follow use-by and storage guidance rather than relying on smell.
- •Ask another person to check food when spoilage is uncertain.
- •Maintain refrigerator temperatures and safe food-handling practices.
- •Check personal hygiene, clothing and household odours through routine rather than relying solely on smell.
- •Use texture, temperature, colour and safe seasoning to improve food enjoyment.
- •Avoid excessive salt, sugar or chilli used to compensate for reduced flavour.
- •Seek dietetic advice if weight loss, reduced appetite or nutritional deficiency develops.
- •Maintain oral hygiene because flavour changes may affect eating habits.
- •Stop smoking and avoid inhaled irritants.
- •Use saline irrigation only with sterile, distilled or previously boiled and cooled water.
- •Do not place essential oils, concentrated herbal extracts or caustic substances directly inside the nose.
- •Seek support for anxiety, depression or social withdrawal related to sensory loss.
- •Parosmia may improve gradually but can temporarily make familiar foods smell unpleasant.
- •Record onset, triggers, associated symptoms and changes over time for clinical review.
Cautions & Contraindications
- •Do not treat sudden anosmia with acupuncture or herbs before stroke, head injury and other serious causes have been considered.
- •Do not delay urgent ENT assessment for unilateral obstruction, recurrent bleeding, facial numbness or eye symptoms.
- •Do not use acupuncture over a recent facial or skull fracture.
- •Do not insert needles or herbal substances into the nasal cavity.
- •Do not recommend inhaling irritant, toxic or flammable substances to test or stimulate smell.
- •Do not claim acupuncture or Chinese herbs reliably regenerate the olfactory nerve.
- •Do not claim that temporary tingling, nasal discharge or headache represents neurological recovery.
- •Do not advise stopping medically prescribed allergy, sinus or neurological treatment.
- •Do not use oral herbs when swallowing is unsafe or severe nausea is present.
- •Cāng ěr Zǐ requires correct processing and dose control because toxicity can occur.
- •Xì Xīn requires verified botanical identity and aristolochic-acid safeguards.
- •Mù Tōng must be botanically verified and free from aristolochic acid.
- •Blood-moving herbs require pregnancy, bleeding, anticoagulant and surgical review.
- •Natural musk and endangered-species ingredients must not be used.
- •Gān Cǎo may affect blood pressure, potassium and medicine metabolism.
- •Screen all herbs for allergy, pregnancy, liver or kidney disease and interactions.
- •Do not interpret progressive cognitive, movement or seizure symptoms as Kidney deficiency alone.
- •Do not use unregulated nasal sprays, compounded oils or herbal powders.
Frequently Asked Questions
What is anosmia?+
Anosmia means complete loss of smell. Hyposmia means reduced smell, parosmia means distorted smell and phantosmia means perceiving an odour that is not present [5].
What commonly causes smell loss?+
Common causes include viral infections, COVID-19, allergy, sinusitis, nasal polyps, nasal obstruction, head injury, ageing and some medicines [5].
Why can food seem tasteless?+
Smell contributes substantially to flavour, so loss of smell can make food seem tasteless even when basic taste sensation remains [5].
When does anosmia require urgent care?+
Urgent care is required when sudden smell loss occurs with stroke symptoms, severe headache, seizure, significant head injury, cerebrospinal fluid leakage, visual symptoms or severe systemic illness [5].
What is smell training?+
Smell training is repeated, structured exposure to several familiar non-irritating odours over weeks or months to support olfactory rehabilitation [5].
Can acupuncture restore smell?+
Evidence is insufficient to guarantee restoration. Acupuncture may be considered adjunctively after serious and treatable causes have been investigated [5].
Which TCM patterns may be considered?+
Patterns may include Wind-Cold, Wind-Heat, Lung Qi deficiency, Phlegm-Damp obstruction, Qi-Blood stasis and Kidney essence deficiency [5].
Can nasal oils or herbs be inserted into the nose?+
Concentrated oils, powders and unsterile substances should not be inserted into the nose because irritation, aspiration, infection or toxicity may occur [5].
What safety changes are important?+
Patients should use smoke and gas alarms, follow food-storage dates and avoid relying on smell to identify fire, gas leaks or spoiled food [5].
Can smell loss be permanent?+
Yes. Recovery depends on the cause and may be incomplete, particularly after severe head injury, congenital absence or neurological disease [5].
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Sources & Further Reading
Clinical guidance, red flags and safety notes on this page draw on the following current sources alongside the classical references above.
- Healthdirect Australia · 2025
Australian overview of smell loss, causes, complications, diagnosis and indications for medical review.
- National Health Service · 2026
Clinical information on common causes, medical review and smell training.
- NHS Tayside Right Decisions · 2026
ENT referral guidance identifying upper-respiratory infection, trauma, sinonasal disease and medicines as common causes.
- Bedfordshire Hospitals NHS Foundation Trust · 2023
Patient guidance on common causes, safety precautions and olfactory training.
- World Health Organization · 2008
Standard acupuncture-point nomenclature and anatomical-location methodology.
- World Health Organization · 2020
International benchmarks for acupuncture competence, safety and professional practice.
Educational reference for licensed practitioners. Not a substitute for individual clinical assessment. Refer to conventional care for any red-flag or undiagnosed presentation.