Loss or change of taste and smell are common among those with PASC. With this symptom, you may also experience “reduced enjoyment of food” and a sense of depression. There is a risk of safety related issues like not being able to smell smoke, gas, and spoiled food. This symptom generally goes away after two months, but some people experience this symptom for longer. Higher viral load results in higher prevalence of olfactory and taste dysfunction. This symptom is experienced more in women, younger age groups, and healthier people. It’s important not to decrease food intake while experiencing these symptoms.
One possible explanation for loss of taste and smell is the obstruction or damage of the respiratory cleft, which prevents air from reaching the cells involved in smell. This obstruction is likely caused by inflammation, as nasal congestion and discharge are not commonly reported with loss of taste and smell and inflammation is already known to be part of the body’s response to COVID-19.
Because some people still experience loss of taste and smell after respiratory symptoms disappear, it is likely that this is not the only cause of loss of taste and smell. Other human coronaviruses are known to infect nervous system cells, so it is hypothesized that COVID-19 may do this as well. Loss of taste and smell might be caused by infection of the cells responsible for smell and taste, resulting in dysfunction or death of these cells and therefore the inability to smell and taste. Over time, these cells can regenerate, and taste and smell can return.
Risk factors that may increase the likelihood of developing loss of taste and smell are heavy drinking, head injury, history of multiple ear infections, smoking, nose/facial injury, and allergies.
Seeing a Doctor for Loss or Change of Taste and Smell
If you decide you would like to seek professional help in managing this symptom, you should first talk to your primary care provider. Your primary provider may refer you to a specialist, such as an ear, nose, and throat doctor. Diagnostic tests for loss of taste and smell include measuring the lowest strength of an odor that a person can smell, comparing tastes and smells of different chemicals, “scratch and sniff” tests, and “sip, spit, and rinse” tests where chemicals are places on specific areas of the tongue.
Self-Care for Loss or Change of Taste and Smell
The best evidence-based treatment option is olfactory training, also known as scent training. Visit our Self-Care Scent Training Module for more information.