Odor disorder (olfactory disorder) – causes, symptoms & treatment

Odour disorder (olfactory disturbance)

An odor disorder or olfactory disorder refers to all disturbances related to the sense of smell. This can affect both hypersensitivity to certain odors and reduced olfactory ability.

What is an odor disorder?

Schematic representation of the anatomy of the nose and the olfactory and olfactory nerves. Click to enlarge.

Medicine basically distinguishes three types of an odor disorder: on the one hand, there are patients who suffer from the so-called hyperosmia – this is how a hypersensitivity to certain fragrances is called.

The opposite is hyposmia – with this symptom there is an insensitivity to certain stimuli. A significant limitation of the sense of smell up to the complete loss of the ability to smell, in turn, is also referred to as anosmia in technical language. All three types of odor disorders are roughly summarized as quantitative odor disorders.

On the other hand, there are the qualitative disturbances of the ability to smell – this is the name given to altered perceptions of a fragrance. Patients who suffer from such qualitative disorders either perceive odors even though they are not present or perceive existing odors strongly changed.

Odor disorders are quite widespread in Germany – after all, about 80,000 people go to the doctor every year due to a changed ability to smell.


The causes of odor disorders are basically divided into sinunasal and non-sinunasal causes. The former are usually due to diseases of the nose or paranasal sinuses. The non-sinunasal causes, in turn, are usually damage to the olfactory system.

In the case of allergies or polyps, for example, there is often a change or even failure of the olfactory system – only in rare cases is a serious disease such as a brain tumor behind the disorders. Even anatomical irregularities such as a crooked nasal septum or other malpositions can lead to the ability to smell being limited or altered.

Non-sinunasal causes for this symptom are, for example, side effects of medication, head injuries or contact with a wide variety of irritants.

Pregnant women also often complain of a reduced or altered ability to smell – but after the child is born, these symptoms usually pass by themselves. In Alzheimer’s, an odor disorder is also very common – after all, about 80 to 90 percent of Alzheimer’s patients are affected by olfactory disorders.

Symptoms, complaints & signs

An odor disorder can cause different symptoms depending on its type and severity. Typically, with dysosmia, there is a noticeable decrease in the sense of smell. The affected person can no longer perceive certain odors or only weakly, often certain odors are perceived as unpleasant.

Phantosmia manifests itself by the fact that smells are perceived that are not present. In parosmia, familiar smells are perceived differently and perceived as unpleasant or irritating. Pseudoosmia is accompanied by a reinterpretation of odors. This unconscious “bad smell” is usually associated with other mental complaints.

In olfactory intolerance, those affected react very sensitively to odors, usually psychological causes are also the basis. In the case of a quantitative olfactory disorder, fragrances have a stronger or lesser effect than usual. Depending on its shape, quantitative olfactory disorder may be associated with a complete loss of olfactory ability or tolerance to certain fragrances.

In most cases, the sense of smell is greatly reduced and the affected person can perceive scents much worse. What the various odor disorders have in common is that they are no longer perceived as such after some time. A habituation quickly sets in and the absence of odors is concealed, for example, by overseasoning food or using excessive amounts of deodorant.


In many of the patients, the odor disorder disappears on its own within a few days. For other people, however, comprehensive examinations are necessary to first clarify the exact causes.

Accordingly, the treatment of these patients is difficult and the odor disorder can drag on for weeks or even months or become chronic.


The odor disorder itself does not constitute a complication, nor does it have a negative effect on the patient’s health. Therefore, life expectancy with an odor disorder is not reduced and there are no further complaints and complications with this disease. However, the disorder reduces the quality of life and complicates the patient’s everyday life.

Likewise, it is no longer possible to enjoy food and liquids in the usual way. In dangerous situations, the odor disorder can lead to death in the worst case, if certain dangers cannot be recognized due to the lack of sense of smell. Furthermore, the smell disorder can also lead to psychological complaints and depression.

The affected person is socially excluded or ashamed of his illness. Treatment of the odour disorder is only possible to a limited extent. In many cases, the affected person has to spend his entire life with the disorder. However, treatment can be carried out with the help of antibiotics or zinc. Whether this will be successful, however, cannot be predicted. Life expectancy is not affected by the odor disorder and is not reduced.

When to go to the doctor?

In many cases, there are no significant problems in everyday life with an odor disorder. People who suffer from an impairment of smell should nevertheless consult a doctor. If the changes are minimal in direct comparison to the fellow human beings, a visit to the doctor is recommended to determine the cause and to be able to assess the course of the disease.

A detailed explanation of the disease and the discussion of warning signals are essential in order to avoid a life-threatening condition in everyday life. If the impairments increase, the consultation of a doctor is necessary. If there is shortness of breath, interruptions in breathing or the development of fears, a doctor should be consulted. If the fears trigger behavioral changes, if there is a social withdrawal or a social phobia, a doctor’s visit is necessary.

In case of pain of the head, a feeling of pressure in the head, a runny nose or nosebleeds, it is advisable to consult a doctor. In case of nasal congestion, nasal speech or swelling in the nose, a doctor should be consulted. If the affected person suffers from dizziness, nausea or vomiting, a doctor is needed. In individual cases, a suddenly acute, health-threatening condition occurs. In these cases, an ambulance service must be called so that there is no threat to life.

Treatment & Therapy

In order to guarantee efficient treatment, the doctor will first ask the patient exactly about the extent of the disease. Above all, it is important to know how exactly the type of odor disorder manifests itself or whether there are other complaints such as a disturbance of the sense of taste.

Subsequently, the doctor will examine the nose including olfactory cleft and throat closely. On the basis of olfactory tests, it is usually possible to provide more precise information about the type of odor disorder – in some patients, however, comprehensive neurological examinations are also necessary. The therapy usually depends on the underlying cause. In the case of an anatomical change, such as a crooked nasal septum as the cause of the odor disorder, this can easily be corrected surgically.

For other causes, however, treatment can be quite difficult. If hormonal causes of the disease are the basis, hormone replacement may help. Steroids, and antibiotics are also often used – but to what extent these can really help against odor disorders is still largely unexplored and controversial.

Patients can count themselves lucky if the odor disorder disappears on its own within a few days.

Outlook & Forecast

The prognosis for an olfactory or smell disorder depends on whether it is a temporary disturbance of the sense of smell or a permanent olfactory disturbance or a complete failure of the sense of smell.

Olfactory disorder is a complex problem. This has a better prognosis, especially in younger people. Unfortunately, previous therapeutic approaches are not always successful. In addition, age-related olfactory disorders are just as untreatable as a congenital odor disorder. It is known that about two-thirds of all sufferers who experience olfactory disturbances after a viral infection experience spontaneous improvements. In one third of patients, the odor disorder persists permanently.

The prognosis is quite good if drugs or pollutants have triggered the disturbance of the sense of smell. Most often, the disorders recede when the drug is discontinued. In the case of pollutant exposures, avoidance of the triggering substance must be achieved in order to improve the prognosis. Odor disorders often occur after severe sinus-nasal infections and diseases of the respiratory system. As soon as the treatment takes effect, the symptoms disappear in many cases.

It is different if the ability to smell has arisen as a result of a head injury or surgery. In these cases, the prognosis can only be positive for a small proportion of those affected. The conditions for complete improvement are individually different and depend on the causes.


There is hardly any direct prevention against the odour disturbance. However, if you already suffer from this and know the exact cause, you can at least try to contain it. If, for example, medication is the trigger for the olfactory disorder, it is advisable to switch to another drug.


Direct possibilities of aftercare are usually not possible in the case of an odor disorder. It cannot be universally predicted whether the odor disorder can be completely cured. First and foremost, those affected are dependent on medical treatment by a doctor so that further complications can be prevented. The way of treatment of this disorder depends very much on the exact cause.

In some cases, medication or antibiotics may be used to treat the condition. The person concerned must always pay attention to a regular intake of the medication. Parents must also pay attention to the regular intake of medicines in their children. Antibiotics should not be taken together with alcohol, otherwise their effect will be weakened.

In some cases, the odor disorder disappears on its own, so that no direct treatment or aftercare is necessary. However, it can also occur throughout life. If a certain substance is responsible for the odor disorder, it must of course be avoided.

In many cases, contact with other sufferers of the disease is also useful, as it can lead to an exchange of helpful information. The life expectancy of the patient is not limited by this disorder.

What you can do yourself

In everyday life, special care should be taken in the event of an olfactory disorder. Targeted measures for a cure or alleviation of the symptoms can not be taken by the person concerned. The focus for the patient should be on the prevention of further complaints and the avoidance of health risks.

Places where toxic substances can be inhaled must be left immediately. Food should only be consumed if it has been purchased commercially and can therefore be ruled out that it is toxic or incompatible. Due to the lack of smell, an important warning signal in case of danger has failed for the person concerned. As a result, food abroad should only be consumed after consultation and protection by locals.

In this way, it can be ensured that they are edible. The consumption of foods whose minimum shelf life has expired should be avoided. If the cold chain has been interrupted in the case of fresh dairy products, meat or sausage products, they must always be disposed of. Unusual discoloration on the food is also an indication of a non-edible product.

Staying in closed premises or garages with exhaust fumes, chemicals or paints is a danger zone. In these cases, an accompanying person who can refer to a possible risk of poisoning in good time is helpful. In addition, it is advisable to wear a mouth guard in the designated rooms.

Lisa Newlon
 | Website

Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.