Lost Scents: How COVID-19 Changed Our Understanding of Smell Disorders
In early 2020, a strange new symptom began to pop up among patients infected with COVID-19: they couldn’t smell. Not just a stuffy nose, but a profound, sudden loss of smell—anosmia—that often came without warning or congestion. It was disorienting, unsettling, and in many cases, long-lasting. Before the pandemic, most people barely gave their sense of smell a second thought. But after COVID-19, olfaction—the invisible, often underappreciated sense—took center stage. What was once a fringe topic in neurology and ENT clinics is now one of the most talked-about sensory disorders in modern medicine. This global smell crisis didn’t just affect individual lives—it redefined how science and society understand olfactory dysfunction.
The Invisible Loss
It's immediately apparent to others when someone loses their vision or hearing. But smell? You could lose it entirely, and no one around you would know. That’s part of what made COVID-related anosmia so insidious—and so psychologically damaging. Smell is deeply tied to flavor, memory, safety, and emotion.
People with anosmia often report:
Food tasting like cardboard
A diminished interest in eating, sometimes leading to malnutrition
Anxiety about not detecting smoke, gas leaks, or spoiled food
A sense of emotional detachment, as though the world has gone flat
For many, this loss became one of the most haunting and lingering symptoms of COVID-19.
A Global Wake-Up Call
Pre-COVID, smell disorders were rarely taken seriously—even in clinical settings. Doctors might overlook anosmia or dismiss it as a minor inconvenience. But the pandemic revealed just how common, complex, and life-altering these disorders can be.
Some key shifts COVID-19 brought to light:
Anosmia is common. An estimated 60–80% of COVID-19 patients experienced some degree of smell loss.
Recovery is unpredictable. Some regain smell in days; others take months—or never fully recover.
Parosmia (distorted smell) and phantosmia (phantom smells) emerged as secondary symptoms, further complicating recovery.
Olfactory nerve damage and inflammation appear to be major culprits—not just nasal congestion.
For the first time, smell disorders were publicly acknowledged on a global scale.
The pandemic became the largest real-time case study in olfactory science history.
Rewiring the Brain: The Science Behind Smell Loss
Smell is the only sense with a direct neural connection to the brain’s emotional and memory centers—the amygdala and hippocampus. This makes it particularly vulnerable to viral disruption and inflammation. When the SARS-CoV-2 virus infects support cells in the olfactory epithelium (the tissue in your nose responsible for detecting odor molecules), it can trigger an inflammatory response that damages olfactory neurons. These neurons typically regenerate, but for some, the process is slow or incomplete. Researchers also discovered that prolonged smell loss is often not about the nose at all—but about how the brain interprets and reconstructs olfactory signals. In other words, COVID may have scrambled your internal "smell software."
The Rise of Smell Training
In the wake of widespread anosmia, people began searching for solutions. One of the most promising? Smell training. This involves repeatedly sniffing specific scents—like rose, lemon, eucalyptus, and clove—twice a day, over weeks or months. Think of it as physical therapy for your nose and brain. Studies show that it can help stimulate neural regrowth and recalibrate the brain’s olfactory map. COVID-19 turned smell training into a mainstream practice, and now it's being studied not just for recovery—but for enhancing olfactory function in the general population.A New Era of Olfactory Awareness
If there's a silver lining to the pandemic’s scent crisis, it’s this: the world woke up to the power of smell. Medical schools are now giving more attention to olfactory disorders. Mental health experts are studying the link between smell loss and depression. Tech companies are exploring digital scent delivery. Artists and chefs are rethinking flavor design for people with altered smell perception. We’ve only just begun to scratch the surface.
What COVID-19 Taught Us About Smell
COVID-19 didn’t just rob millions of people of their sense of smell—it shattered our collective ignorance about how important this sense really is. It showed us that smell isn’t a luxury—it’s foundational to how we experience food, memory, intimacy, and even identity. In a world reeling from invisible losses, smell became a symbol of what we take for granted—and what we must now fight to understand, protect, and restore.
