
COVID-19, flu and colds are all upper-respiratory infections that share many common symptoms. This can make it hard to tell which illness you have. To complicate matters, it’s possible to have one or more of these viral infections at the same time. We hope our handy symptoms chart, composed with information from the CDC, helps you decipher COVID-19 vs. flu vs. colds so that you can get the right treatment for you.
Symptoms onset.
The time it takes a person to begin to show symptoms after being exposed to a virus varies by person and by condition, but here are some general guidelines.
COVID-19: Symptoms typically appear 5 days after being infected, but may appear 2 to 14 days after infection. As noted above, the time range can vary significantly, especially among variants such as Delta and Omicron, for example.
Flu: Anywhere from 1 to 4 days after infection.
Colds: Symptoms of a cold usually peak within 2 to 3 days.

Symptoms checker.
During cold and flu season, you may have to look a little more closely at your symptoms to make sense of what’s going on in your body. Here’s a list of the main symptoms of COVID-19, flu and colds and how they might look for each illness.
Sore throat
COVID-19: Sometimes
Flu: Sometimes
Cold: Common
Stuffy/runny nose
COVID-19: Rare
Flu: Sometimes
Cold: Common
Cough
COVID-19: Yes, typically dry
Flu: Yes
Cold: Mild to moderate
Muscle aches
COVID-19: Yes
Flu: Yes, often
Cold: Slight
Headache
COVID-19: Sometimes
Flu: Yes
Cold: Rare
Fever
COVID-19: Yes
Flu: Yes, often high
Cold: Rare
Fatigue/weakness
COVID-19: Yes
Flu: Yes
Cold: Mild
Sneezing
COVID-19: No
Flu: Sometimes
Cold: Common
Shortness of breath
COVID-19: Yes
Flu: Yes
Cold: Rare
Loss of taste or smell
COVID-19: Yes
Flu: Rare
Cold: Sometimes (due to nasal congestion)
Diarrhea/vomiting
COVID-19: Sometimes
Flu: Uncommon
Cold: No
The best way to protect yourself and your loved ones from severe complications of COVID-19 and flu is to get vaccinated. The CDC recommends an annual flu shot for most people age 6 months and older. Updated recommendations for COVID-19 vaccines, booster shots and additional doses can be found on the CDC’s website.
Frequent handwashing, masking and social distancing can also help you avoid the germs that cause COVID-19, flu and colds.
When to seek emergency medical attention
Seek emergency medical care immediately if someone is experiencing these emergency warning signs —even if you’re not sure what may be causing them:
COVID-19
- Trouble breathing
- Persistent pain or pressure in the chest
- New confusion
- Inability to wake or stay awake
- Pale, gray or blue-colored* skin, lips or nail beds (*depending on skin tone)
Flu
- Any of the emergency signs for COVID-19
- Excessive vomiting
- Dehydration
- High fever
At Medical City Healthcare, we’re dedicated to the care and improvement of human life. So, we hope you’ll Take Care!
Medical City Healthcare provides comprehensive emergency services across North Texas.
A reminder: Medical City Healthcare ERs are not COVID-19 testing sites. Please only use an ER in an emergency. For questions about COVID-19, please call (833) 582-1974. Be aware that wait times may be long due to high call volume. If you need a COVID-19 test and have no symptoms, please visit your county’s health department website. You can also visit 211texas.org or vaccines.gov for testing and vaccine information and locations.
For more information, call our Ask a Nurse hotline 24/7 or use Find a Doctor online.
You can also get care for minor injuries or illness at one of the many DFW CareNow® Urgent Care locations, with convenient Web Check-In® so you can wait in the comfort of your home.
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