Nurse practitioner Julie Sabo at Marysville Primary Care says it's all in the eyes.
"The younger kids, their eyes get all red," she said, referring to a sure sign the little one is battling the flu.
"High fevers; it's not typical. It's the 101-103 fevers. They get the running nose, the cough. And adults, you feel like a truck has hit you," said Sabo.
The Center for Disease Control reports influenza activity is high across most of the United States and widespread in just about every state -- including Ohio.
Union County is no exception. Eric Keifer, laboratory director at Memorial Hospital of Union County, says the numbers show the county has hit some high numbers compared to years past.
Since October, MHUC labs have found 164 flu cases. That is 40 more than each of the two most recent high activity years, 2009-2010 and 2010-2011. In December alone the hospital found 86 cases of Type A flu and 12 cases of Type B flu.
MHUC's Urgent Care reports approximately 700 flu cases have been seen from November 2012 to date. That is triple the number of flu cases in the same months last year.
And that does not include the in-office tests that individual physicians run in their offices.
"It was really bad just before Christmas. Each of us were seeing two or three a day and now I haven't seen anything the last couple of days," said Sabo. "We haven't had a lot of the hospitalizations but we've been giving the flu mist and flu shots. We're still immunizing."
Once doctors identify the flu, treatment needs to happen quickly.
"You have to treat it in the first 24 to 48 hours with Tamiflu otherwise you have to ride it out," said Sabo.
Influenza is a contagious respiratory illness caused by flu viruses and is different from the average cold. It comes on suddenly and has a variety of symptoms including fever or feeling feverish/chills, cough, sore throat, runny or stuffy nose, muscle or body aches, headaches, and fatigue.
Keeping a safe distance from people with flu is important because it can spread to others up to six feet away.
The CDC reports most healthy adults may be able to infect others beginning one day before symptoms develop and five to seven days after becoming sick. Children may pass the virus for longer than seven days. Symptoms start one to four days after the virus enters the body.
Sabo said she thinks the numbers locally have dropped off because of the holiday break. Children staying home instead of going to school kept the flu from spreading even more. And in fact, she believes people going to work while sick may be a major contributor to the widespread outbreak.
"They don't stay home when they're supposed to. They go to work when they're sick or they think they're feeling better," said Sabo.
And in line with all the other tips to stay healthy, she said to wash your hands frequently.