What's the Difference Between a Cold, the Flu and COVID-19?

 As we move closer to winter, preventing viral illnesses becomes a top priority. With COVID-19 still spreading, many are wondering whether we could face a "twindemic"—a challenging flu season combined with the ongoing pandemic to overwhelm an already taxed healthcare system. 

"We don't know what these viruses are going to do," says Dr. Michelle Shukhman, an internal medicine specialist at Cedars-Sinai. "They could mix together to inundate the body, or they could somehow cancel each other out."

Plus, because we're taking COVID-19 precautions—practicing physical distancing, wearing a mask and paying extra attention to hand hygiene—we might even see a decrease in colds and flu this year.

Regardless of how it plays out, if you feel a tickle in your throat or spike a fever, it's natural to wonder what you're experiencing. The good news? The treatment for each of these viruses is largely the same: rest, get plenty of fluids, and treat symptoms such as fever and body aches with over-the-counter medicine. 

Still wondering about the differences (and similarities) between the three? Here's how it breaks down.

Flu

While the coronavirus continues to make headlines, influenza (flu) is also a serious disease that can lead to illness or even death. 

An estimated 39 to 56 million Americans came down with the flu last season, according to the Centers for Disease Control and Prevention. Almost half of them were so ill they paid a visit to their healthcare providers.

"The flu spreads mainly through respiratory droplets that travel through the air when we talk, sing, cough or sneeze," Dr. Shukhman says. It's also possible for a person to get infected with the flu by touching the same surface as someone who is infected, or by shaking hands or sharing cups and glasses.

Most people who get the flu develop symptoms within four days of infection, and those symptoms usually resolve within two weeks. Unlike COVID-19, a vaccine is available now—so the best way to protect yourself is to get a flu shot and continue to practice good hand hygiene. 

COVID-19

Coronavirus is an entire family of viruses, which like the flu, mainly spreads through respiratory droplets. Four of these viruses are similar to the common cold in terms of symptoms and severity. The novel coronavirus, or SARS-CoV-2, is a potentially deadly virus that can lead to COVID-19.