How to tell the difference between COVID-19 and influenza

Story by: Norton Healthcare on November 22, 2022

COVID-19 and the seasonal flu have some of the same signs and can range from no symptoms to severe illness.

Both infections can cause:

• Fever or chills
• Cough
• Difficulty breathing
• Fatigue
• Sore throat
• Runny or stuffy nose
• Body aches
• Headache
• Vomiting and diarrhea (more common in children than adults)

One frequent symptom of COVID-19 that doesn’t come with flu is a newly lost sense of taste or smell.

Emergency warning signs of infection from the coronavirus include:

• Trouble breathing
• Persistent pain or pressure in the chest
• New confusion
• Inability to wake or stay awake
• Bluish lips or face

With either illness, contact a health care provider with any severe or troubling symptoms.

It can be difficult to tell based solely on symptoms whether an illness is COVID-19 or flu. Confirmation of either would have to come from a nasal swab test.

The common cold typically comes with a runny, stuffy nose, sneezing, sore throat and body aches. Fever is not a common cold symptom, and while fever often accompanies flu, it doesn’t always.

Who’s vulnerable to COVID-19 or flu?

Anyone can get sick from the coronavirus or the flu — or both. Serious complications from these viruses can happen at any age.

Those who are older and those with severe underlying medical conditions like heart or lung disease or diabetes seem to be at higher risk for developing more serious illness with COVID-19.

Similarly, the flu can strike anyone. As with COVID-19, anyone over 65 and people of any age with certain chronic conditions such heart or lung disease, diabetes, or asthma are at higher risk of developing serious flu complications. Flu can hit pregnant women and children under age 5 particularly hard. Kids younger than 2 years old are especially at risk.

Signs and Symptoms	COVID-19	Cold	Influenza	Allergies
Symptom onset	Abrupt	Gradual	Abrupt	Abrupt
Fever	Common	Rare	Usually; lasts 3 to 4 days	No
Aches	Sometimes	Slight	Usually; often severe	No
Chills	Common	Uncommon	Fairly common	No
Fatigue, weakness	Sometimes	Sometimes	Usually	Sometimes
Sneezing	Rare	Common	Sometimes	Common
Stuffy nose	Rare	Common	Sometimes	Common
Sore throat	Sometimes	Common	Common	No
Chest discomfort, cough	Common	Mild to moderate; hacking cough	Common; can be severe	Sometimes
Headache	Sometimes	Rare	Common	Sometimes
Extreme exhaustion	Sometimes	Never	Common	No
Shortness of breath	When serious	Rare	Rare	Sometimes
Runny nose	Rare	Common	Sometimes	Common
Diarrhea	Sometimes	No	Sometimes	No
New loss of taste or smell	Common	No	No	No