Your guide to loss of smell
Our guide to loss of smell provides you with helpful information about the disease. You also have the opportunity to clarify your questions quickly and easily in an online doctor’s consultation via video. You can obtain prescriptions or sick notes at the doctor’s discretion via the app. No appointment problems or long waits.
Guide to odor loss
What causes a loss of smell and what diseases does this symptom indicate? Find out more here.
Many people notice a temporary loss of smell in the course of a cold, flu-like infection or influenza. Patients with the novel coronavirus Sars-CoV-2 also sometimes report a loss of taste and smell. The symptoms often subside once the illness in question has been cured. However, a permanent loss of smell can also occur.
Abstract
- Every year, an estimated 50,000 people in Germany experience a loss of taste and/or smell.
- Causes can be viral diseases.
- Loss of smell can also be an early symptom in Parkinson’s and dementia patients.
Definition
The smell of coffee, fresh flowers or sliced citrus fruits can awaken the spirits. However, those who suffer from loss of smell no longer perceive it.
The generic term for olfactory disorders is dysosmia. A distinction is made between different forms:
- Complete loss of smell (anosmia)
- Reduced sense of smell (hyposmia)
- False odor perception (parosmia)
- Hypersensitivity to odors (hyperosmia)
Anosmia is often associated with a loss of taste. The nose plays a key role in the perception of flavors. The taste of a meal is only fully perceived when the corresponding molecules pass from the oral cavity to the nose during chewing.
How does the sense of smell work?
The olfactory epithelium is located in the roof of the nose and contains around 30 million olfactory cells. These are equipped with very fine hairs (the cilia). When scents reach the target cells, the information is transmitted via the olfactory fibers ( filae olfactoriae ) to the olfactory bulb ( bulbus olfactorius ) and from there to the brain.
Humans are thus able to distinguish between over 10,000 different odors.
Women have a more pronounced sense of smell than men.
Causes
On the one hand, one possible reason for a loss of smell may lie directly in the nose. On the other hand, olfactory signals are not or not fully transmitted to the brain. The following table presents typical diseases and symptoms of both possibilities:
| Mechanical / sinunasal causes (directly in the nose) | Sensory / sensorineural causes (misdirection of olfactory signals) |
| Sinusitis | Destruction of the olfactory cells after a severe cold |
| Nasal polyps | Viral diseases |
| Crooked nasal septum | Taking medication (especially antibiotics) |
| Swollen mucous membranes due to allergies | Smoking |
| Craniocerebral trauma after an accident | |
| Neurodegenerative diseases (Parkinson’s, dementia) | |
| Brain tumors |
In rare cases, a lack of sense of smell is congenital.
Depending on the cause, the ability to smell returns in many cases. This is often the case after a cold has subsided, nasal polyps have been removed and swelling of the mucous membranes due to allergies has subsided. Even if smoking is stopped, the olfactory senses usually recover after a while.
The situation is different in the case of traumatic brain injury: if the olfactory center is damaged, four out of five people affected will have a permanent impairment.
In the case of a viral infection such as Sars-CoV-2 or influenza, the reason for the loss of smell is not a blocked nose. Viruses attack the olfactory nerves. How long the disorder lasts, for example in the case of an infection with the novel coronavirus, has not yet been researched. Other viral diseases indicate that the loss can last up to several months. In some cases, it is one of the first symptoms to appear.
Treatment options: What to do about odor loss?
Disorders of the sense of smell caused by medication or allergies are easy to treat: After stopping the medication or treating the allergic symptoms, the ability to smell usually returns. Nasal polyps can be operated on and a crooked nasal septum can be straightened.
Targeted olfactory training can also help. Those affected sniff four different olfactory pens every morning for a period of six months. These felt-tip pens filled with a specific fragrance oil are held under both nostrils for around three seconds. The benefit is proven, but the reason is hardly: it is assumed that olfactory cells grow back and the brain learns to process the odor signals again.
When should I go to the doctor?
If you notice a disturbance in your sense of smell without a recognizable cause (e.g. a blocked nose), you should consult a doctor.
If an infection with Sars-CoV-2 is suspected, it is recommended that you first call your family doctor. Alternatively, you should follow the instructions issued by the respective municipality or local authority.
How does the doctor make the diagnosis?
Anyone who notices a sudden loss of smell should consult an ENT specialist. To establish the diagnosis, he performs a rhinoscopy. He also uses an endoscope to determine whether any changes can be observed in the nasal mucosa.
An olfactory test provides information about the type and severity of dysosmia. Strong odours such as tar, fish or coffee are detected and differentiated. It is also possible to check what concentration of odorants can still be detected.
If the doctor can rule out a direct cause in the nose, he will use a computer tomography scan to determine whether it is a sensorineural olfactory disorder.
Questions and answers
What consequences can dysosmia have?
The loss of the sense of taste that often accompanies the loss of smell can mean a great loss of quality of life for those affected. Last but not least, the sense of smell has a warning function: if smoke or the smell of gas can no longer be perceived, this can be life-threatening in certain situations.
Those affected often do not recognize spoiled food in time. They therefore suffer more frequently from food poisoning.
Does loss of smell occur more frequently in old age?
In fact, a diminishing sense of smell is a consequence of the ageing process. This ability can start to decline from around the age of 40. Around one in two people over the age of 80 report a partial or complete loss of smell, even in the absence of a disease.
Sources
- https://www.uniklinikum-dresden.de/de/das-klinikum/kliniken-polikliniken-institute/hno/forschung/interdisziplinaeres-zentrum-fuer-riechen-und-schmecken/downloads/downloads/Patienteninformationen_08.pdf
- https://www.apotheken-umschau.de/Nase/Anosmie-Nicht-mehr-riechen-koennen-302191.html
- https://www.aerzteblatt.de/nachrichten/78152/Morbus-Parkinson-Geruchsverlust-geht-Diagnose-um-bis-zu-zehn-Jahre-voraus
- https://www.aerzteblatt.de/archiv/133861/Riechstoerungen
- https://science.orf.at/stories/3200444/
- https://www.pharmazeutische-zeitung.de/ausgabe-342013/vom-guten-riecher-verlassen/
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- Zuletzt aktualisiert: 28. May 2026
