Is Loss of Smell and Taste a Sure Sign of Coronavirus?

Dr. Hira Tanveer

3 min read


One of the most important symptoms of COVID-19 infection includes loss of smell. This symptom can be accompanied by loss of taste sensation, has been added to the list of symptoms of the coronavirus. Most importantly, however, this symptom should not be taken into consideration alone, as many other respiratory infections can also cause loss of sensation. 

The attention to this symptom of COVID-19 was called by many clinicians and healthcare providers around the world. The American Academy of Otolaryngology recently called for a loss of smell sensation and taste sensation to be added to the list of screening tools for the coronavirus. Similarly, the NHS in May also added these symptoms officially to the COVID-19 list. 

The addition of these symptoms will have a positive impact on early detection and treatment initiation. If an otherwise asymptomatic person develops sudden loss of smell and taste sensation, he is ten times more likely to be positive for COVID-19. It is, therefore, helpful in recognizing asymptomatic patients and quarantining such patients before they spread the disease. 

Additionally, since these are preliminary findings, the World Health Organization is working to establish the link between the symptoms and the disease.  These symptoms are temporary, as the sense of smell and taste return soon. 

These symptoms came to light when many physicians noted an increase in the cases of ‘isolated anosmia’—loss of smell, in the regions of the UK, US, Italy, and France. 

Why does anosmia occur?

There are many viruses especially those that affect the upper respiratory tract, which can have the side effect of anosmia. Such viruses—over 200 in number—give rise to the common cold and congestive nose. Even the previously described coronaviruses are known to affect the sense of smell in 10 to 15 percent of the cases. It is, therefore, no surprise that the novel coronavirus can do the same.

According to the charity Fifth Sense’s director of medical affairs, Professor Carl Philpott, this happens because the viruses cause nasal congestion. This congestion leads to the falling-off of the fine hair-like endings of the smell receptor cells. As a result, these receptors are not able to pick up odor from the molecules. 

It is hypothesized that covid-19 virus causes some sort of inflammation in the olfactory nerve, instead of damaging the smell receptors. Moreover, this effect is compounded by the high concentration of the virus in the nose. Consequently, there is a transient loss of smell sensation, lasting for a week or two. 

Slowly, the sense of smell recovers as the nasal symptoms get better, and there are less membrane edema and nasal congestion. In only one percent of the cases, patients complain of persistent loss of taste and smell. 

As to the loss of sense of taste, Professor Philpott explains, that this could be linked to the loss of sense of smell. The loss of sense of smell has a significant impact on the way we perceive flavor; because the sense of smell is impacted by the virus, it could lead to a loss in taste. Researchers say that most people can’t separate the sense of smell and taste, and because both are perceived together, the loss of one seems like the loss of both. 

In people with known allergies, the loss of smell and taste is even more common if they are infected with COVID-19. However, there are other health conditions such as neurodegenerative disorders, nasal polyps, or head trauma that can impact the sense of smell and loss in taste sensation. 

What should you do if you develop a sudden loss of smell and taste sensation?

Sudden anosmia and loss of taste sensation mean higher chances of having COVID-19. These symptoms should not be taken into consideration alone, rather, the whole condition of the patient with questions about fever, cough, history of travel/contact, should be asked, along with confirmatory blood tests, to rule in the possibility of infection. As mentioned before, the chances of sudden anosmia in a healthy person, are highly suggestive of coronavirus, but other conditions should not be excluded. 

If a healthy person suddenly develops symptoms of coronavirus, including anosmia and loss of taste, then they should isolate themselves. Even those with mild symptoms are encouraged to avoid going out of their homes for at least seven days. If you live with other people, then your family members should also avoid going out, as they could be carriers. 

What are the other symptoms of COVID-19?

According to the World Health Organization, the commonest symptoms of COVID-19 remain fever, fatigue, and dry cough. Additionally, there can be tiredness, sore throat, conjunctivitis, headache, a skin rash, and diarrhea. 

For most people, the symptoms of COVID-19 are mild, and last 7 to 14 days. During this period, it is best to stay hydrated, get up and move about at regular intervals, and take paracetamol for fever. 

In case of worsening shortness of breath, returning fever, or chest pain, it is best to seek medical help. 

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Disclaimer: The contents of this article are intended to raise awareness about common health issues and should not be viewed as sound medical advice for your specific condition. You should always consult with a licensed medical practitioner prior to following any suggestions outlined in this article or adopting any treatment protocol based on the contents of this article.

Dr. Hira Tanveer - Author Dr. Hira Tanveer is an MBBS doctor and currently serving at CMH Lahore. Writing is her favorite hobby as she loves to share professional advice on trendy healthcare issues, general well-being, a healthy diet, and lifestyle.