Doctors say there are key differences between the cold and flu

We're deep into flu season, but just because you feel sick doesn't automatically mean it's the flu.

Doctors say this time of year, many people mistakenly believe they have the flu, when it could be a cold or something else entirely.

"We tend to call a lot of things 'the flu'," said Dr. Susan Rehm with the Cleveland Clinic. "As a matter of fact, people get diarrhea and they say they have the flu. Well, the flu is a respiratory illness, it's not a gastrointestinal illness."

Here's a quick guide:

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To clear up the confusion and get the right treatment for your illness, doctors say it's important to rule out the flu. For an easy way to remember the symptoms, think of the word FACTS:

F - Fever

A - Aches

C - Chills

T - Tiredness

S - Sudden symptoms

If those things sound familiar, it could be the flu, so tell your doctor so they can get you the right treatment.