The loss of smell and/or taste, whether partial or total, initially represented a distinctive sign of Covid-19, but it also characterizes other conditions, especially infectious ones in the ENT sphere. Therefore, we can lose our sense of smell after a cold, a strong flu, sinusitis, and also in the case of other diseases.
Causes of Loss or Impairment of the Sense of Smell
The sense of smell plays a crucial role in our daily experience, allowing us to savor the aroma of food, enjoy our favorite fragrances, and detect unpleasant odors. Often, we do not give it importance until we find ourselves in the unfortunate situation where our nose no longer perceives any evident smell, even though we are aware that it is there.
- Sinusitis, an inflammation of the nasal mucosa and sinuses, can lead to temporary or permanent loss of the sense of smell. Inflammation in the sinuses interferes with the ability of olfactory receptors to detect and transmit smell signals to the brain.
- Allergic rhinitis can also be associated with the loss of the sense of smell. Allergic reactions to pollen, dust, or other substances can cause inflammation of the nasal mucosa and interfere with the ability of olfactory receptors to function properly.
- Severe cranio-cerebral trauma, such as accidents or serious falls, can affect the olfactory nerves that send smell signals from the nose to the brain. This can lead to partial or total loss of the sense of smell.
- Some individuals are born with congenital anomalies that can affect the normal development of olfactory receptors or the neural pathways associated with the sense of smell. These anomalies can result in permanent loss of the sense of smell.
Types of Smell Impairment
There are several medical terms used to describe dysfunctions associated with the sense of smell, namely parosmia, hyposmia, or anosmia. Parosmia, as mentioned earlier, is the umbrella term for dysfunctions that can affect a person’s sense of smell. Therefore, someone with parosmia can detect smells, but at a lower intensity or may only perceive certain odors.
This type of dysfunction can occur after an illness, an accident, or may be congenital. Changes in the sense of smell can be permanent or temporary.
Hyposmia refers strictly to a person’s inability to fully perceive the smells around them, while anosmia refers to the inability to detect certain types of smells. This can be temporary or permanent and is a primary symptom of COVID-19, according to the World Health Organization. Hyposmia can also occur following other types of viral infections or cranial injuries.
Solutions for Accelerating the Recovery of the Sense of Smell
The loss or impairment of the sense of smell can have a significant impact on a person’s quality of life. Aside from COVID-19 infection, there are several potential causes for this problem. It is important to identify the underlying cause and take appropriate measures to accelerate the recovery of the sense of smell. Smell exercises, vitamin B supplements, and olfactory therapy can be useful solutions in this regard. If the loss of smell persists or worsens, it is always recommended to seek the advice of a medical specialist for proper evaluation and treatment.
- Smell exercises, which we will detail further. Performing smell exercises can help stimulate and restore olfactory receptors. These exercises may involve smelling certain substances, such as essential oils, multiple times a day to train and reactivate the olfactory receptors.
- Vitamin supplements, especially vitamin B. There is some evidence suggesting that certain vitamins, particularly vitamin B, may have a beneficial impact on the health of the olfactory sense. Consulting a doctor and dietary supplementation with vitamin B may be helpful in accelerating the recovery of the sense of smell.
- Treating the underlying cause. If the loss or impairment of the sense of smell is caused by underlying conditions, such as sinusitis or allergic rhinitis, treating these conditions may be essential for the recovery of the sense of smell. Consult a specialist to identify the underlying cause and obtain appropriate treatment.
- Olfactory therapy: Olfactory therapy is an approach in which individuals are regularly exposed to intense and distinct smells under the supervision of a specialist. This therapy aims to restore neural connections and stimulate the recovery of olfactory receptors.
Considering that the recovery of these senses may take several weeks, health experts encourage practicing smell exercises, which could help in regaining the senses more quickly. Research is still in its early stages, but the results are promising, so this type of exercise is worth trying.
According to a recent study, a series of specific smell exercises can reactivate this sense in patients recovering from respiratory infections like COVID-19 or other conditions.
The study was published in the journal The Laryngoscope, and scientists analyzed data collected from 153 patients in Germany who suffered from post-infectious olfactory dysfunction due to certain conditions between 2008 and 2018.
Patients received smell training kits consisting of various products with intense aromas, such as eucalyptus, rose, chocolate, lavender, coffee, lemon, clove, and thyme. Participants were initially tested to assess the intensity of their sense of smell and again after six months of smell exercises.
Following this experiment, researchers obtained promising results, with participants showing improvement in their ability to smell. Individuals with parosmia, a dysfunction of the sense of smell where the person has very little or no developed sense of smell, along with older individuals, also showed improvements.
The authors of the study concluded that smell training can accelerate the process of regaining this sense by stimulating the ability to identify different smells and distinguish between them.
How Can Smell Exercises Help You?
Smell exercises refer to the repeated exposure of a patient to different types of aromas in an attempt to stimulate their ability to detect smells around them. Although the exact mechanism behind this type of exercise is not yet known, researchers believe that they are closely related to the unique regenerative ability of the olfactory nerve.
The olfactory nerve is, in fact, a pair of cranial nerves that transmit information from smell receptors in the nose to the brain. It is believed that repeated exposure to smells can promote the neurogenerative capacity of the cells in the nasal area responsible for smell. These, in turn, can support the repair process of damaged olfactory nerves.
According to researchers, smell exercises could even improve overall brain activity. This phenomenon is due to a complex process to which patients practicing smell exercises are subjected.
Thus, through these exercises, patients are usually asked to try to smell certain objects and think about how that object might smell at the same time. At each session, different aromas are tried to vary the range of smells and increase the complexity of the exercise.
The authors of the aforementioned study recommend practicing these exercises twice a day. At each session, four different aromas will be used, and each aroma will be smelled for about 30 seconds. For individuals with unknown or very old smell problems, the exercises should be practiced for at least four months.
However, scientists note that there is currently no established standard regarding the practice of these exercises, and their recommendations are based on empirical research. Additionally, although different types of aromas have been used in existing studies, there is relevant information regarding the effectiveness of items with aromas from the aromatic, fruity, and floral categories.
How Effective Are Smell Exercises?
Currently, the effectiveness of smell exercises is still debated. There are double-blind studies suggesting an improvement in the recovery of the sense of smell over time, without any type of exercise in this regard. It is also important to note that most studies conducted on smell exercises are not double-blind, meaning that participants in the study are aware that the exercises are for regaining smell. Therefore, there is not total control over performance differences from one patient to another, which can affect the quality of the reported conclusions.
Although there are still many questions awaiting answers, it is certain that smell exercises have improved the quality of life for some patients and are free of risks or adverse reactions, which is why they are worth trying.
Last but not least, researchers recommend these exercises because they can provide a good opportunity to practice concentration and imagination skills, efforts that have a positive impact on cognitive functions and overall brain activity. Thus, even those who cannot smell the odors around them at all can benefit from a few minutes a day spent trying to smell certain aromas.
