Can You Smell This?

Imagine sipping the coffee you have enjoyed for a lifetime, only to find it tastes like soap. You initially assume there is residue in your mug until someone else tastes it and says it’s fine.

That distorted taste is called parosmia, a condition caused by changes in smell. The more people understand smell loss, the better chance they have of recovering and even detecting debilitating diseases earlier.

If you experience smell loss or changes in smell that don’t return to normal, it’s time to reach out to your doctor. David Lerner, M.D., an otolaryngologist at the University of Miami Health System, is passionate about researching and treating loss of smell.

Dr. Lerner first became interested in smell as a resident at Mount Sinai Hospital in New York during the pandemic. “We had all these patients with smell loss in my last few years of residency. This huge population of patients was miserable, and no one knew what to do with them,” he says.

Before COVID, the loss of smell was a relatively obscure topic in medical research, with only a handful of scientists dedicated to studying it. Today, awareness has increased, and research is growing steadily.

“The short answer on smell loss is that it’s an exciting, interesting field that’s now popular. The downside is that there aren’t a lot of effective treatments yet,” says Dr. Lerner.

What causes smell loss?

Smell loss is most commonly caused by a virus, like COVID-19, or an infection, like sinusitis. “In COVID, it wasn’t uncommon to read about people who were smelling gasoline or cigarette smoke even when it wasn’t there,” says Dr. Lerner.

For most people, smell loss caused by illness is temporary. 

There are different kinds of smell disorders, some with a change in the degree of smell and some with a change in the quality of smell:

1. Anosmia: A total loss of smell
2. Hyposmia: A degree of smell loss
3. Parosmia: A distorted sense of smell, such as rotten or fecal smells.
4. Dysgeusia: This distorted sense of taste, such as garlic suddenly tasting like rotting meat, often results from smell loss.

Treating patients with chronic sinus disease that causes loss of smell with intranasal steroid sprays should improve their olfactory abilities. Some individuals may eventually require sinus surgery.

“You shouldn’t just accept smell loss. You should see someone who can look into whether you have chronic inflammation,” says Dr. Lerner.

Some sense of smell can decline with natural aging. Some medications, such as certain antibiotics, statins, and antithyroid medications, can also cause a decreased ability to smell.

Smell loss as an early sign of neurodegenerative disease

When an infection or virus isn’t the culprit of unresolved smell loss in older adults, studies show it can be an early sign of neurodegenerative diseases like dementia and Parkinson’s. It’s not unusual for Dr. Lerner to meet patients recently diagnosed with Alzheimer’s who lost their sense of smell years before diagnosis.

The olfactory area in your nose is one of the few areas of the adult human body where new neurons are created. You need new nerves to turn over to keep smelling, but he says a neurodegenerative disease causes an issue with this process.

“It’s like a canary in the coal mine for your nervous system health,” says Dr. Lerner.

Dr. Lerner emphasizes that older adults with a pronounced loss of smell should speak to a healthcare provider and get a thorough evaluation.

Many people don’t appreciate their sense of smell until they lose it.

“My patients are really bothered by it. They’re more unhappy than you’d think,” says Dr. Lerner.

Your sense of smell doesn’t only bring pleasure, like the smell of grass after rain or flowers blooming in the spring. Your smell also keeps you safe. This can include smelling burning food on the stove, recognizing spoiled food or detecting leaking gas.

Smell is also closely tied to taste, making it hard to enjoy food without a sense of smell.

“Without smell, people don’t enjoy food and don’t want to go to restaurants or go out with friends. Patients consistently tell me their quality of life is way worse,” says Dr. Lerner.

According to the NIH, nearly 1 in 5 Americans over 40 report some change in sense or taste.

That number increases with age.

“I’ve been surprised that the more I ask people about it, the more common it is. For a long time, people have been told there’s nothing to do about it.”

A 2021 study of smell during COVID-19 estimated that about 40% to 75% of people with the virus experienced smell loss. Most people regained their sense of smell, but it remains a symptom of long COVID for some people.

Once smell loss became a known symptom of COVID-19, more people took the condition seriously. This matters because, in some cases, smell can be regained with treatment. Other times, an unresolved sense of smell can be an early red flag of a more serious condition.

What is the treatment for the loss of your sense of smell?

People with smell alterations from an infection or virus usually improve after the illness subsides. For example, if smell loss comes from chronic sinus inflammation, anti-inflammatory medication such as nasal sprays can solve the problem.

For those who don’t naturally regain their sense of smell, smell therapy (olfactory retraining) kits readily available online can help. Research shows that smelling four strong scents a few times a day for three months and switching them to four other scents can improve smell.

Some people report improvement from taking supplements like Omega-3s. However, Dr. Lerner ran a study using a high dose of omega-3s for smell loss in people with long-term COVID and didn’t find any clear improvement.

A new study on a platelet-rich plasma injection in the nose has had promising results.

Dr. Lerner hopes that raising awareness of smell loss will lead to widely available treatment in the coming years. “Patients are miserable without their sense of smell, and it’s more common than you would think,” he says.

Key takeaways for smell loss

1. Talk to your doctor. Smell loss may be treated by identifying and addressing the cause, including an illness or medication side effect.
2. Aging adults should know that pronounced loss of smell that doesn’t return may be an early symptom of a neurodegenerative disease. Speak to your doctor to see if you need additional testing.
3. Try using a smell kit purchased online as directed.

By Wendy Margolin, a contributor for UHealth’s news service.

Tags: Dr. David Lerner, Olfactory dysfunction, Olfactory retraining, otolaryngology in Miami, Smell therapy