The coronavirus can manifest in many different ways, and it's hard to know which direction your case is headed in. After all, you could develop symptoms so severe you need emergency medical care, or you could barely feel anything at all. Luckily, new research may help determine how your case will play out—especially when it comes to one particular symptom. According to a new study, if you experience loss of smell, you're more likely to only have a mild COVID case. Read on to find out more about the correlation between this symptom and the severity of your condition, and for more on symptoms that may make you breathe a sigh of relief, If This Is Your Only Symptom, You Might Be Safe From COVID.
The study, published in the Journal of Internal Medicine on Jan. 5, looked at 2,581 COVID patients from 18 different European hospitals from March to June 2020. Researchers found that the prevalence of loss of smell, otherwise known as olfactory dysfunction (OD), was much higher in those who had mild cases than those who ended up suffering with moderate to critical cases.
According to the study, 74 percent of the patients observed reported the loss of smell as one of their symptoms. Nearly 86 percent of patients with OD experienced a mild COVID case, while only 4 to 7 percent of those with OD had moderate-to-critical cases.
The study divided patients into three categories: mild, moderate, and critical. Mild patients were described as those "without evidence of viral pneumonia or hypoxia," who were likely to live out their illness at home. Moderate patients were those who had "clinical signs of pneumonia," such as fever, cough, shortness of breath, and fast breathing, but no indication of severe pneumonia. Critical patients, however, did have clinical signs of pneumonia alongside either a respiratory rate of more than 30 breaths per minute, severe respiratory distress, or blood oxygen levels of less than 90 percent.
Moreover, the study concluded that it's unlikely OD from COVID will be permanent. According to researchers, people's sense of smell usually reappeared after 18 to 21 days, and 95 percent of patients had regained their sense of smell at least six months after their infection. An early July study from Science Advances concluded that this is because the virus changes the sense of smell by targeting the function of supporting cells, not directly infecting olfactory sensory neurons—which means it's unlikely to cause permanent damage to those neurons responsible for smell.
The American Academy of Otolaryngology-Head and Neck Surgery says that loss of smell has even been seen in COVID-positive patients who experience no other symptoms. However, loss of smell alone doesn't necessarily point to coronavirus. For more issues that could be causing your loss of smell, keep reading, and for other notable symptoms, If You Have These 4 Symptoms, You Could Have Longer Immunity to COVID.
Colds are the most common cause of partial and temporary loss of smell, according to Healthline. This illness can cause "irritation to the mucus membranes lining the nose," which causes the loss of smell. And for more common coronavirus symptoms, These Are The Most Common Early Signs You Have COVID, Study Finds.
Seasonal allergies are also a common cause of loss of smell, allergist John Cohn, MD, told The Health Nexus. However, you're likely to have other common allergy symptoms that aren't associated with COVID, he says. This includes congestion, sneezing, wheezing, itchy nose and throat, itchy eyes and ears, sinus congestion, and post-nasal drip. And for signs you've passed a coronavirus infection, If You Have This Subtle Symptom, You Might Have Already Had COVID.
Nasal polyps are benign growths that line the tissues of your nose. According to Healthline, the polyps can be triggered by a number of things, such as chronic sinus infections, asthma, hay fever, cystic fibrosis, Churg-Strauss syndrome, and sensitivity to non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or aspirin. They cause loss of smell because they physically block the passage of air into the nose. And for more up-to-date information, sign up for our daily newsletter.
Just because your loss of smell isn't COVID doesn't mean it isn't serious. According to Healthline, brain or nerve damage from conditions such as diabetes, an underactive thyroid, brain tumors, Alzheimer's, and more can result in the loss of smell. There are "receptors inside the nose that send information through nerves to the brain," and if any part of this pathway is damaged, loss of smell ensues. And for more serious issues to be aware of, This Rare Symptom Could Mean You Have a Severe COVID Case.