Symptoms usually include dry cough, fever, and shortness of breath. But there is evidence that the complete loss of the smell – and often the taste – is early signs of new coronavirus infection.
So far, there is currently no hard evidence on this, although many have taken to social media to report smell loss alongside other COVID-19 symptoms. As yet, it has not been listed by Public Health England or on the NHS website as an official symptom to look out for. But in this rapidly evolving situation, this may change.
So why is it that people are reporting a loss of smell and taste from this virus? First, it’s worth clarifying that when we eat, we smell and taste together.
Try pinching your nose when you eat and see what your food “tastes” like. You’ll find that the only things you will detect is if the food is salty, sweet, sour, bitter or savoury. This is because these elements of flavour come from the taste buds on the tongue. Losing the smell of food leads many people to think their taste has gone when in the vast majority of cases it will be intact.
But sometimes even when other symptoms disappear, your sense of smell doesn’t return – or in some cases it’s reduced (hyposmia), or is distorted (parosmia).
In these cases, the virus has damaged the smell receptors causing them to lose the fine, hair-like endings that allow them to pick up smell molecules from the nasal mucus. Previous studies have looked at which viruses cause this condition – and many have been implicated, including the coronavirus family of which COVID-19 is a member.