Stop. Smell. Be well.

COVID-19 Smell Check

Your nose knows

Sudden loss of the sense of smell is one of the earliest signs and best predictors of COVID-19. Put your nose to work to keep yourself and others healthy. Perform daily smell checks to catch COVID-19 in its tracks and prevent its spread.

How Ag Sciences is fighting COVID

Food Science might not be the first discipline that comes to mind in the battle against COVID-19. But in the spring of 2020, anecdotes of anosmia (the inability to smell) associated with coronavirus infection began to appear. More and more patients reported experiencing a sudden inability to smell. Researchers in the Penn State Department of Food Science were unexpectedly but uniquely prepared to investigate the connection. They quickly emerged as leaders in global research on COVID-19 and sudden smell loss.

Pivoting to meet a new challenge

Before the COVID-19 pandemic, Penn State food scientists Dr. John Hayes and Dr. Alyssa Bakke used their expertise in taste biology, psychology, flavor perception, and other disciplines to better understand the human sensory experience. Their work in the Penn State Sensory Evaluation Center isn't focused only on controlled taste tests to quantify and optimize consumer products. They and fellow researchers also study human smell and taste perception directly to better understand how people differ in their sensory experiences.

The research team saw that they could redirect their expertise to COVID-19.

Working with over 600 clinicians, scientists, and patient advocates in more than 40 countries, Penn State researchers developed, distributed, and analyzed data from surveys that expanded and solidified our understanding of the virus’s link to anosmia (the inability to smell) and hyposmia (reduced ability to smell). More than 25,000 participants responded to a survey on behalf of the Global Consortium for Chemosensory Research. The results determined that 50 to 75 percent of those infected with COVID-19 experienced smell and/or taste disturbances, establishing smell loss as a more accurate predictor of infection than cough or fever.

As research continues, scientists are optimistic that smell checks will become an effective public health tool that can be used to predict COVID-19 infection and mitigate its spread.

What you need to do

Stop Smell Be Well

Test your smell each day.

You can use your morning coffee, food, flowers, spices, perfume—you name it. Stop and take careful notice of whether or not you can smell.

Be safe when you check.

  • Perform your sniff test alone with your mask off—and be sure to mask back up!
  • Even if you can smell, don’t throw caution to the wind. Always practice preventive behavior like social distancing, mask use, and frequent handwashing.

Make it a habit.

  • Mark your calendar. Set an alarm. Make a daily smell check as routine as washing your face or brushing your teeth.
  • Actively and intentionally pay attention to your sense of smell each day.

If you can’t smell familiar scents, take action.

 Self-isolate until you speak with a healthcare professional:

The science behind it all

It's not just there to hold up your sunglasses—your nose is a sophisticated piece of diagnostic equipment

Anosmia is the inability to smell, and can occur with viral illness or head trauma. Sudden and unexplained loss of the sense of smell has emerged as a critical diagnostic marker of COVID-19.

How It Works

COVID-19’s first stop in the human body are support cells in the top of the nasal cavity. These cells express lots of the ACE2 receptor that the virus uses to sneak into cells. When these cells are attacked, we can’t smell because of local inflammation that disrupts our smell receptors, the link between odors and our brain.

As many as 75 percent of those infected with COVID report smell loss. Anosmia is one of the earliest  signs and accurate predictors of COVID-19. In fact, it’s a better diagnostic symptom than fever and cough. That’s even more true with those who don’t otherwise feel unwell. Unlike other viruses, many people with COVID-19 can experience smell loss without a runny nose or any congestion.  

Remember—Anosmia is just one symptom of COVID-19.

Even if your sense of smell is working, you may not be in the clear. Also monitor yourself for all of the symptoms indicated by the Centers for Disease Control and Prevention. If you exhibit symptoms or have been in contact with someone who has, self-isolate and contact University Health Services, your campus health center, or your primary care provider.

COVID-19 symptoms to watch for:

  • Fever or chills
  • Cough
  • Shortness of breath or difficulty breathing
  • Fatigue
  • Muscle or body aches
  • Headache
  • New loss of taste or smell
  • Sore throat
  • Congestion or runny nose
  • Nausea or vomiting
  • Diarrhea


Penn State COVID-19 Tools and Information

In the News: COVID-19 and Sense of Smell

The Penn State Sensory Evaluation Center in the College of Agricultural Sciences is a hub of efforts to understand the link between anosmia and COVID-19. We’re hard at work with researchers, clinicians, and patients around the world. Together, we will nose out new ways to keep our community safe.