Flu season is right around the corner in many parts of the United States. Like years before, doctors recommend taking preventative measures like washing your hands and covering your mouth and nose when sick — advice that seems commonplace in COVID-19.

Ara Chrissian, MD, is an interventional pulmonologist and critical care physician at Loma Linda University Health who regularly cares for patients hospitalized with COVID-19. He says the threat of flu paired with COVID-19 could be extremely dangerous, but using proper precautions and knowing the symptoms can help limit the spread. “By not taking preventative measures, such as the recommended flu vaccine, the flu season and the coronavirus pandemic could synergistically overwhelm the healthcare system,” Chrissian says.

The two viruses spread in a similar manner: mainly through respiratory droplets created during talking, coughing or sneezing. Chrissian says the flu and COVID-19 viruses also have many symptoms in common. “They both can cause fever, cough, shortness of breath, headache, stuffy nose, body aches, sore throat, and exhaustion or fatigue. These symptoms alone cannot be used to differentiate between the two,” he says. “However, understanding some differences may help us suspect one over the other, optimize therapy and aid in limiting spread.”

Flu, not COVID-19

According to the Centers for Disease Control and Prevention (CDC), adults who have the flu seem to be most contagious during the first four days of illness but may remain contagious for up to seven days. “With the flu, it’s possible to spread the virus for about seven days, with one of those days being before symptoms show in the sick person,” Chrissian says.

Most people who get the flu will recover in as short as a few days, and if they don’t develop complications, they can avoid hospitalization and recover completely. Fortunately, for patients who require medical attention, healthcare professionals are no stranger to the flu and are well equipped to treat it.

For flu patients, Chrissian says FDA-approved prescription influenza antiviral drugs are a great line of defense. “Those who may be hospitalized with flu or at higher risk for flu complications are treated with antiviral drugs as soon as possible and watched for new or worsening symptoms by providers who know how to fight this familiar beast,” he says.

Perhaps the most considerable difference in the two respiratory viruses is the availability of preventative treatments. “There are several approved influenza vaccines created each year in anticipation of the viruses likely to circulate that season,” Chrissian says. “The best and simplest way to protect yourself from the flu and help reduce the spread of the virus is to get vaccinated. There is yet no vaccine to prevent COVID-19.”

COVID-19, not flu

A characteristic symptom of COVID-19 is a change in or loss of taste or smell. While this does not occur in everyone who gets COVID-19 and is also a symptom seen with common cold viral infections, it has not been associated with the flu. Additionally, if you know when you were exposed to someone with an illness, Chrissian says you can have a better idea of how long you may be contagious, even if you have mild or no symptoms.

“A person with COVID-19 can potentially spread the virus for up to twice as long as someone with the flu,” Chrissian says. “However, there are likely many factors that contribute to one’s contagiousness, which we are still learning.” He also says the higher degree and duration of contagion seems to be especially notable in the elderly and those with certain underlying health conditions.

The CDC also states that COVID-19 has been linked to more superspreading events than flu, meaning the virus spreads more quickly and easily than influenza.

There are also additional complications common with COVID-19 which are not consistent with the flu, including multisystem inflammatory syndrome in children, and the development of blood clots in the veins and arteries, leading to a stroke or heart attack.

When treating COVID-19, providers stay updated as new treatment options and a better understanding of the virus emerges. “We are still learning the full extent of how the virus impacts the body. Many studies, both nationally and globally, are underway to find the best treatments,” Chrissian says.

This article was originally published on the Loma Linda University Health news site