Reduced sense of smell, known as anosmia, has emerged as one of the hallmark symptoms of COVID-19. This is the first symptom for some patients, and sometimes the only one. Often accompanied by inability to taste, anosmia occurs suddenly and severely in these patients, almost as if a reversal has occurred.
Most regain their sense of smell and taste after recovering, usually within weeks. But in a minority of patients, the loss persists, and doctors cannot say when or when the sensations will return.
Little is known about how the virus causes chronic anosmia or how it is cured. But things are coming up as the coronavirus spreads worldwide, and some experts fear that the pandemic could leave large numbers of people with permanent loss of smell and taste.
Smell is closely linked to both taste and flavor, and anosmia often makes people enjoy eating. But the sudden presence may also have a major impact on mood and quality of life. Studies have linked anosmia to social isolation and anhedonia, an inability to feel happiness, as well as a strange sense of separation.
British scientists studied the experiences of 9,000 COVID-19 patients who joined the Facebook support group. Many members said that not only did they lose pleasure in eating, but also in social interaction. The loss had weakened their connections with others, leaving them feeling lonely, even away from reality.
“From a public health perspective, this is very important,” said Dr. Sandeep Robert Datta, associate professor of neurobiology at Harvard Medical School. “If you think around the world about the number of people with COVID, even if only 10% would have lost a longer smell, we are talking about millions of potential people. ”
Perhaps the most direct effects are nutrition. People with anosmia can continue to perceive basic tastes, but smell adds complexity to the perception of taste through the hundreds of odor receptors that characterize the brain.
Many people who cannot smell will lose their appetite, putting them at risk of nutritional deficiencies and unexpected weight loss.
Smells will also be a key warning system that warns people of dangers in our environment, such as gas leaks. One sense of smell in old age is one reason that older people are more prone to accidents, such as fires caused by leaving burnt food on the stove.