Sep 30
Understanding the Differences and Similarities: Common Cold, Flu, and COVID-19

Understanding the Differences and Similarities: Common Cold, Flu, and COVID-19

This time of year is often referred to as “flu season” for good reason. As the temperatures decrease and more people stay indoors, the chances of people catching the common cold or flu increase. And because COVID-19 is still rampant, it can be hard to know what virus is causing symptoms if you get sick. Our partners at the UW of Pharmacy helped put together the chart and information below to refresh our knowledge and understanding of these three illnesses.

Important Note: This information is not meant to help support a diagnosis. Because symptoms often overlap among the different viruses, and those who catch the coronavirus can experience symptoms ranging from mild to severe, it’s important to always isolate and get tested for COVID-19 if experiencing any of the symptoms below.

Cold Influenza COVID-19
Cough Usually Usually (dry) Usually (dry, persistent)
Muscle Aches Sometimes Usually (often severe) Usually
Tiredness Sometimes Usually (2-3 weeks) Usually
Sneezing Usually Sometimes Rarely
Sore Throat Usually Usually Usually
Runny/Stuffy Nose Usually Sometimes Usually
Fever Sometimes Usually (not always) Usually
Diarrhea Never Sometimes (kids) Sometimes
Nausea/Vomiting Never Sometimes (kids) Sometimes
Shortness of Breath Sometimes Usually Usually
New Loss of Taste/Smell Sometimes (with congestion) Sometimes Usually (often without congestion)

How contagious are these illnesses?
COVID spreads more easily than the flu or a cold.

  • Cold: People with a cold are contagious 1-2 days before symptoms appear, are most contagious the first 2-3 days, and remain contagious until all symptoms are gone (usually 1-2 weeks).
  • Flu: Generally, people with the flu are contagious 1-2 days before showing symptoms and are most contagious the first 3-4 days.
  • COVID: It is possible for someone with COVID to spread the virus 2 days before experiencing symptoms, and they may remain contagious for 10 days after symptoms appear or 10 days after testing positive, even if they were asymptomatic or symptoms have resolved.

Though these illnesses are extremely contagious, they are often preventable.

  • Wash your hands regularly with soap and water
  • Cover your mouth and nose when sneezing or coughing
  • Stay home when you’re sick
  • Continue wearing a mask
  • Keep a safe distance (6 feet) from other people
  • Whenever entering a facility (hospitals, senior living community, etc.), make sure to drop by at a Temperature Scanning Kiosk for a quick temperature check
  • Adults 65 and older should receive the high dose influenza vaccine annually to provide the strongest protection
  • Those who have not received the COVID-19 vaccine should sign up to get vaccinated


Information provided by: Eileen Tran (Pharmacy Student), UW School of Pharmacy Class of 2023