With multiple respiratory viruses swirling this time of year, it can be hard to know which sickness you’re dealing with. But with cases of flu on the rise in much of the country, it’s important to know the signs of this virus — and doctors say there are some telltale signs.
“Symptoms of the flu are pretty consistent from year to year,” said Dr. Hilary Babcock, chief quality officer at BJC Healthcare and an infectious disease doctor at Washington University in St. Louis. It’s likely that the symptoms you’ve associated with flu for years are still a sign of the sickness, but some can be more telling than others.
Below, doctors share just what the most common signs of the flu are.
Frequently reported flu symptoms include fever, chills, muscle aches, sore throat and upper respiratory symptoms.
“Most of the time [people] have fever, sometimes chills, muscle aches, [and] can have some sore throat” in addition to upper respiratory symptoms like cough and nasal congestion, Babcock said.
The cough that’s associated with flu is often a dry cough, according to Dr. Marcel Curlin, an associate professor of medicine in the division of infectious diseases at Oregon Health and Science University’s school of medicine.
Many of these symptoms overlap with those of COVID-19 and the common cold, so be sure to take a COVID test before assuming you have the flu. And either way, it’s important to stay away from other people if you have signs of sickness so you don’t spread your virus to others.
Loss of appetite is also common.
People who are infected with the flu often experience a lack of hunger, Curlin said.
But even if you don’t have much of an appetite, it’s important to maintain fluid intake while you’re sick. The amount of fluids each person needs varies based on one’s gender, size and symptoms, but you should keep in mind that fever-induced sweating and even blowing your nose can reduce the amount of fluids in your body.
Having lots of water or hot tea is a good idea when you’re feeling crummy.
Kids may have a few additional symptoms.
The symptoms above are associated with adults, but children can suffer from a few other ailments, too.
“Kids will often have gastrointestinal symptoms, maybe some diarrhea or nausea, that doesn’t usually happen in adults,” Curlin said.
Unlike other respiratory viruses, flu comes on fast.
When compared to colds or other respiratory viruses, the flu comes on quickly, according to Babcock.
For example, someone with the flu will likely feel sick all at once, without warning signs like an early sore throat or a runny nose. You might start feeling lousy one afternoon without having noticed anything off at all in the previous days.
“What people often describe first is sudden onset of fever,” Curlin said.
Your infection should improve in several days, so get in touch with your doctor if it doesn’t.
“Symptoms are typically worst in the first few days of infection,” said Dr. Cory Fisher, a family medicine physician at Cleveland Clinic, who noted that your symptoms should get better over a week or so.
You can treat mild symptoms with fluids, rest and time, Fisher said.
But for some people, such as immunocompromised folks and older patients, symptoms can become serious. Difficulty breathing is one sign that the virus is getting worse, Curlin said, and could be a sign of severe disease.
“Influenza kills many people every year in the United States,” Curlin noted.
If you notice worsening symptoms after a few days of improvement, it’s important that you contact your doctor, Fisher said.
A flu shot is a good way to stay healthy this season.
“The most important thing that someone can do is get the flu vaccine every year,” Babcock said.
In fact, the vaccine offers better protection than some people assume.
“Often people will look at reports about the effectiveness of the vaccine, and they may see something that says its effectiveness this season is 50%, and they’re like, ‘Well, that may or may not work,’” Babcock said. “But what that really means is that it cuts your chance of getting the flu in half.”
It’s also not too late in the season to get one, she noted.
“If you don’t want to get the flu, that’s still the most important thing that you can do,” she said.