Not being able to taste your coffee in the morning or smell the candle you lit can catch you off-guard, but a sudden loss of taste and smell are two of the most distinguished symptoms of COVID-19.
Smell loss can be one of the first, or only, signs of COVID-19 and often will appear before other symptoms.
According to the Journal of Internal Medicine, nearly 86% of people with mild COVID-19 cases report a loss of smell or taste, while more critical cases report only 7% of people losing those senses.
The study suggests that for people whose smell and tastes senses remain intact while they have COVID-19 may have a worse disease course or may be more likely to be hospitalized or placed on a ventilator. This means that people who lose taste or smell may have a more mild infection.
Why does the virus cause a loss of taste and smell?
It’s not completely clear why COVID-19 affects taste and smell for so many. It’s believed that the virus is causing an inflammatory reaction or damage inside the nose that leads to a loss of olfactory – or smell – neurons. For some people, change is permanent, but in others, the neurons can regenerate.
“The virus really doesn’t hit your taste, it’s hitting your smell. When your sense of smell is lost, your taste is often affected, too, because the olfactory sensors in your nose control both,” said Dr. Matthew Brookes, otolaryngologist (ear, nose and throat specialist) with Marshfield Medical Center – Eau Claire. “You also may notice change to your subjective taste, meaning things may taste strange or things smell differently or are unpleasant.”
What can you do?
Like any damage in the body, it will take time for the receptor cells to heal, and there are no guarantees they ever will depending on the extent of damage done by the virus. While most people who lose their smell and taste due to COVID-19 regain those senses, it may take months for them to return. For others, it may never return.
“You may start to regain some smell, and even if things smell different, it’s a good sign if you can smell anything,” said Dr. Brookes. “Even if it’s not quite back at 100%, it’s a good sign.”
One study shared the loss of taste and smell often disappears within three weeks, and 95% of people regained their normal sense of smell and taste within six months.
Smell therapies may be an option for regaining your sense of smell. Therapy involves smelling certain scents multiple times a day to encourage the brain to reconnect. The goal with scent training is to repeatedly expose the brain to certain smells to help encourage the ability to detect those scents.
Dr. Brookes suggests trying essential oils, shampoos or strong smelling foods – like citrus foods – to help regain smell. It’s best to pick an array of scents – like something fruity and something floral.
“Try to expose yourself more often to those certain smells, and think about what that scent should actually smell like while you’re smelling it,” Dr. Brookes said. “You have to retrain your nerves and your brain to reconnect that to your memory of that smell.”
While the effect of smell therapy is still being evaluated, Dr. Brookes says it doesn’t hurt to try and people can start the therapy as soon as they experience symptoms.
If you did lose taste or smell, remember – safety first
One effect often not considered when losing taste or smell is the dangers it can leave behind. If you don’t stay cautious and take preventive actions, you may be vulnerable to things such as food poisoning and fire.
“If you can’t smell, check your smoke and carbon monoxide detectors,” Dr. Brookes said. “Check food and drink expiration dates. Your sense of taste won’t be able to warn you that you’re eating or drinking something expired. You also may not be able to smell if it’s rotten.”