Doctors say a fever and body aches are the big clues that you have the flu and not a cold. But there is one more virus to throw into the mix that is sending more and more people into emergency rooms.
It's called norovirus. But instead of the fever that comes with the flu, the tell tale sign for norovirus is diarrhea.
There is no vaccine to protect against this one, but the good news is that just like the flu and a cold there is the same prevention.
"Washing hands, covering your mouth, you know washing surfaces and wearing a mask if you are ill so you are not spreading it," says Dr. Marilyn Staines, a critical care doctor.
"If you are sick please don't go to work or school, don't send your kids to school until they are feeling better or aren't contagious," adds Dr. Stanford Ross, an emergency room physician.
Complications with norovirus are dehydration, which is why it is especially important to drink plenty of fluids.