The Flu Killed a Healthy 21-Year-Old Man. Here’s How That Can Happen

Most people view influenza as a routine, if unpleasant, possibility each winter. But the case of a 21-year-old man in Pennsylvania is a poignant reminder that sometimes, the worst-case scenario is more serious than sick days and bed rest.

Kyle Baughman, an aspiring personal trainer living in Latrobe, came home for Christmas not feeling well, his mother, Beverly, told WPXI. His symptoms persisted after returning to work after the holidays. “I think he thought, ‘I just got the flu, I’ll be alright. I’ll go rest a little bit,'” Beverly Baughman told WPXI.

Just a few days later, however, Kyle Baughman died at University of Pittsburgh Medical Center Presbyterian hospital from flu-related organ failure, according to his family.

TIME asked Dr. Peter Shearer, director of the emergency department at the Mount Sinai Hospital in New York City (who was not involved in Baughman’s case), how and why the flu can turn fatal.

Why does the flu turn deadly?

“Influenza can be a very serious illness,” Shearer says. “Even though the vast majority of the public that comes down with actual influenza will get through it with Tylenol, fluids, Motrin, whatever, there are people who do get very sick.”

Deadly cases are mostly limited to the very young, the elderly and those with pre-existing conditions, such as respiratory illnesses, but Shearer says a very small percentage of otherwise healthy people do develop serious complications. “You’ve got a lot more mucus production, coughing, et cetera. It sets you up for possibly a bacterial infection [such as bacterial pneumonia] on top of [flu symptoms],” Shearer says. For some people with pneumonia, “it will spread to their bloodstream and cause an overwhelming, multi-system infection.” While these cases are extremely infrequent, they can sometimes end in death, Shearer says.

What should you do if you have the flu?

Don’t try to ride it out yourself, Shearer says. He recommends visiting your primary care doctor or an urgent care clinic within 48 hours of developing telltale flu symptoms, including cough, fever, runny nose, sore throat and body aches. A doctor can treat you with Tamiflu, an antiviral medication that can mitigate some symptoms and shorten the duration of the illness.

But if you’re seeking treatment, the emergency room shouldn’t necessarily be your first choice, Shearer says, as you’ll run the risk of infecting others and exposing yourself to sicknesses potentially more severe than yours.

How can you tell if the flu is serious?

In most cases, flu symptoms will subside within three to seven days and are mild enough to be treated with over-the-counter painkillers, fluids and rest, Shearer says. If you experience prolonged symptoms, or shortness of breath on par with what you’d feel during strenuous exercise, you should see your doctor to rule out complications, he says.

Is it too late to get a flu shot?

Not at all. “It’s better now than never,” Shearer says. “Flu season, although it is ramping up, is going to continue for another few weeks. If you develop a bit of an immunity now, and you’re exposed in February, it will protect you.”

And while the flu shot isn’t 100% effective, Shearer says that vaccinated people who still get sick will likely have less severe cases than those who never get vaccinated at all.