"We're seeing a lot of mixed illnesses," said Dr. Johnathan Gusdorff, Care STAT.
At Care STAT in Havertown, the number of people coming in each day has more than doubled. And so has the number of people being called in to take care of all the sick people.
"We've actually doubled almost tripled that just to meet the needs of our community," said Dr. Gusdorff.
The Pennsylvania State Health Department is reporting almost 3,200 cases of the flu with the highest numbers in Lehigh and Montgomery counties.
Officials at the Montgomery County Health Department say they've had 420 cases this flu season and last season there were only 69.
Almost all of those cases were of flu strains included in the vaccine. Doctors say if you haven't gotten vaccinated, there's still time to do so.
Flu symptoms include fever, body aches, fatigue, chills and a cough. Dr. Gusdorff says he believes the numbers are higher this season because there weren't many last year.
"People weren't really revving up their immune system with anything flulike," he said.
If you want to boost your immune system, there are some things you can do. Health officials suggest staying hydrated, eating well, exercising, washing your hands often and getting plenty of rest.
It's important to go to the doctor right away if you think you may have the flu. There is medication available to shorten the flu but it must be taken within the first 48 horus.