Children's Hospital Colorado

The Difference Between COVID-19, Cold, Flu and Other Illnesses You May Hear About This Season

Mother taking temperature of her son

Cough, cough. Sniff, sniff. “I don’t feel good,” your kid says. Uh-oh, you think. Could it be COVID-19? It’s a normal reaction. Although getting vaccinated, wearing a face covering, social distancing and frequently washing your hands are the best ways to prevent getting sick with the coronavirus and limit the spread, there’s still a possibility that you or your child may become infected.

Children’s Hospital Colorado infectious disease specialist Samuel Dominguez, MD, PhD, says that although flu and common cold symptoms can be similar to COVID-19 in kids, there are some important differences to know:

  • COVID-19 seems to spread more easily than the influenza virus (the flu) and other respiratory viruses.
  • COVID-19 causes more serious illness in some people than the flu.
  • It takes longer before people show symptoms of COVID-19, and people can be contagious for longer. That’s why testing, quarantine and isolation are so important.
  • There’s a flu vaccine that is readily available and easily accessible. Though the Food and Drug Administration has authorized several safe and effective COVID-19 vaccines for emergency use, it will take time to vaccinate most of the adult population. Plus, we're still waiting on additional data from studies in kids younger than 12.

Even with these differences in mind, it’s challenging for any parent to sort through the symptoms. Seasonal allergies only increase confusion. With the help of our experts, we created the following symptoms chart for quickly comparing the overlapping symptoms of COVID-19, other seasonal respiratory viruses, the flu and allergies.

Symptoms quick chart

Remember, not everyone experiences the same symptoms. You should use this quick chart as a starting point only. If your child is sick, be sure to talk with their pediatrician and ask about getting tested.

And a note about wording: Though terms like “the common cold,” “the flu,” “colds” and “cold viruses,” are often used interchangeably, remember that there are many viruses that cause respiratory symptoms in children. Even when we aren’t facing a pandemic, the severity of and treatments for these illnesses vary, which is why asking an expert is always recommended.

Signs and symptoms in kids COVID-19 (the new coronavirus) Influenza (the flu) Common respiratory infections (colds) Seasonal allergies (hay fever)
Onset of symptoms Varies; typically gradual Sudden Varies Typically sudden or ongoing
New loss of taste or smell Sometimes Uncommon Uncommon Uncommon
Fever Sometimes*; typically high fever Very common; typically high fever Varies Uncommon
Tiredness Severely tired Severely tired Varies Mild
Cough Very common; typically dry cough Very common; typically dry cough Varies Uncommon
Headache Sometimes Very common Varies Uncommon
Loss of appetite Sometimes Common Varies Less common
Muscle and body aches Common Very common Common Uncommon
Sore throat Common Common Common Sometimes; typically mild
Runny nose Common Common Common Very common
Nausea or vomiting Sometimes Sometimes Less common Uncommon
Chills Sometimes Very common Less common Uncommon
Diarrhea Sometimes Sometimes Varies Uncommon
Shortness of breath/breathlessness Sometimes Sometimes Uncommon Uncommon

It can be challenging to identify the cause of symptoms, especially in younger kids. We’ve included additional information about each condition below, signs and symptoms to look for and why testing matters.

*Less than half of children who are diagnosed with COVID-19 will have a fever. Even if your child does not have a fever, it is possible that they could have COVID-19.

Why, when and how to get tested

COVID-19 vs. the flu

COVID-19 vs. a common cold

Common colds are normal. In fact, healthy children get about six colds a year. According to the National Institutes of Health, there are more than 200 different viruses, such as rhinoviruses, that can cause symptoms.

Right now, infectious disease specialists are seeing an uptick in seasonal respiratory viruses they would normally expect in the winter. This off-season resurgence is likely due to the relaxing of social distancing measures and more interaction between groups and families.

“It might be a strange late spring and summer in terms of respiratory disease,” says Dr. Dominguez. 

COVID-19 vs. ear, nose and throat conditions

Some conditions of the ear, nose and throat are often the result of a respiratory illness like a cold or the flu. Interestingly, during the COVID-19 pandemic, doctors are diagnosing fewer ear and sinus infections in children than expected.

“We think this might be related to public health measures like social distancing and school closures, which have resulted in less transmission of the bacteria and viruses that commonly cause these infections,” says Children’s Colorado pediatric otolaryngologist Sarah Gitomer, MD.

Multisystem inflammatory syndrome in children (MIS-C)

COVID-19 is caused by a virus called SARS-CoV-2. When infected with this virus, most children are asymptomatic, meaning they don’t have any symptoms of COVID-19, or they have mild symptoms. In rare cases, though, there are two reasons some children get very sick.

“One is just a really bad COVID-19 infection that occurs during what we call an acute — or sudden — infection,” says Dr. Dominguez. “The other is a new condition called multisystem inflammatory syndrome in children, or MIS-C, which usually occurs 2 to 6 weeks after becoming infected with SARS-CoV-2.”

Cases of COVID-19 continue to ebb and flow. But when COVID-19 case counts increase, experts expect an increase in MIS-C, Dr. Dominguez says. With the 2020 fall and holiday surge in COVID-19 cases, cases of MIS-C also rose dramatically. Although MIS-C is rare, parents should know the symptoms and keep an eye out for them. The best way to prevent MIS-C is to take the same precautions against COVID-19.

The COVID-19 pandemic has been extremely hard on everyone, especially kids and teens. It can be even harder if your child or someone in your family has COVID-19. Now more than ever it’s important to regularly talk with your child and check in with your teen about their physical and mental well-being and help calm their coronavirus anxiety. Carve out time for your own self-care, too. And when appropriate, help your kids make plans to safely see their friends in person in a socially distant setting.

Keeping you safe during the pandemic

If your child needs medical care like surgery, urgent or emergency care, mental healthcare, vaccinations or a checkup for a chronic condition, it's critical that they get the care they need from pediatric experts.

At Children’s Colorado, we’re here to deliver high-quality care for kids who need it in the safest environment possible. From requiring face coverings to implementing visitation and screening policies, learn about all the ways we’re keeping your family safe when you come for a visit.

This page was updated May 6, 2021. Recommendations can change quickly in a public health emergency. Please follow all health and safety guidelines set by your local authorities. Reference the CDC and CDPHE for updates.

Answers in your inbox

Expert advice delivered directly to you. Get weekly tips