You’re coughing, your muscles ache and you have a fever. Is it the flu? Or a cold? How can you possibly tell?
“We all get the winter cold,” Dr. David Cennimo, an assistant professor in medicine and pediatrics in the division of infectious disease at Rutgers New Jersey Medical School, told TODAY. “But, if you ever had full blown influenza you are not mistaking that for a cold.”
The symptoms seem similar when it comes to the common cold and the flu. But there are subtle differences between the two. The experts share how flu differs from a cold. (And they all stress that flu can be prevented by getting the flu vaccine.)
1. High fever is associated with the flu.
While people with colds might feel hot, a fever of 102 degrees or higher often signals that a person has the flu.
“When I see a higher fever, I think first about influenza,” Cennimo said.
Dr. Donald Middleton agreed that high fever is a telltale sign someone's grappling with flu.
“Most of the time you can’t tell. But if you get a high fever of 102 or 103 and severe sore throat and cough that won’t stop, it can be flu,” the family medicine doctor at University of Pittsburgh Medical Center told TODAY.
2. ‘Colds are usually self-healing.’
Even though a cold makes people feel miserable, they normally improve without a doctor’s help.
“Colds are usually self-healing,” Middleton explained.
But sometimes flu requires antiviral medications or hospitalization. It's important to note that the flu can be fatal.
The Centers for Disease Control and Prevention (CDC) reported that the 2017-2018 flu season was a high severity season across all age groups. As of late October 2018, 185 pediatric flu deaths had been reported, and 80 percent of those deaths occurred in children who had not received the flue vaccine.
3. Flu happens abruptly.
When people develop a cold, it normally starts slowly with mild sniffling, sore throat or congestion for a few days. Then it worsens. With flu, it occurs suddenly. People often feel great and then abruptly feel sick.
“Flu comes on very quickly,” Cennimo said. “With a cold, it’s like 'I feel something is going on' and then the next day you feel (sick).”
Dr. Antonio Crespo, an infectious disease specialist at Orlando Health, agreed.
“The rapid onset of fever, headache, body ache and cough, that is most likely to be related to influenza and you should look for medical advice,” he told TODAY. “The best benefit of treatment is when it’s started within 48 hours.”
4. Body aches, sore throat and headache mean flu.
“Influenza tends to be associated with more coughing, more myalgia (body aches), the fatigue, more headache. (With) the common cold, you would have more people complaining of nasal congestion, runny nose, sinus congestion. Less likely to have fever. Less likely to have body aches,” Cennimo said.
Or put more simply:
“The common cold tends to be milder than influenza,” Crespo said.
5. The flu lasts longer and comes with complications.
For the most part, a cold will last about three to five days, then people start feeling better. But anything lasting five or more days could be the flu.
“The influenza lasts a little longer than the common cold,” Crespo said.
People can also develop complications, such as pneumonia and strep throat, more often with the flu.
“With flu you need to pay attention to complications,” he said. “If you feel like you are getting better and you get a fever and a productive cough it could be pneumonia (from the flu).”
If you think you might have the flu, you should visit your doctor as soon as you can.