Flu season has arrived, and the illness has already spread across 35 U.S. states. What can you do to protect yourself?

"Influenza, commonly known as the flu, is a contagious respiratory illness caused by influenza viruses. Flu can cause mild to severe illness and in extreme cases, death." Sandra Stricoff, infection preventionist, Department of Infectious Diseases  at Greenwich Hospital said in a statement. "The predominant strain we're seeing this season is H1N1, which is especially hazardous to younger and middle-aged people."

Sometimes telling the difference between cold and flu symptoms can be tricky' distinguishing the difference is crucial because influenza can lead to more serious health problems such as bacterial infections and pneumonia.

Flu symptoms are almost always more severe than cold symptoms, and can include: Fever and chills; Cough; Sore throat; Runny or stuffy nose; Muscle or body aches; Headaches; Fatigue;Vomiting and diarrhea (these are more common in young children), according to the Center for Disease Control and Prevention (CDC), Greenwich Hospital reported.

Those who are suffering from severe flu symptoms or are at a higher risk of influenza-related infections than the general population should be prescribed antiviral medications. These medicines can shorten the length of the illness and prevent dangerous complications, but are most effective when started early in the illness' progression.

"Prevention is the best medicine" when it comes to influenza, the news release reported.

Getting vaccinated is the primary recommendation in flu prevention, the shot has been approved for anybody above the age of six months.

Other prevention techniques include: frequent hand washing; avoiding other sick individuals; and disinfecting surfaces in the home, classroom and workplace.

"Avoid touching your eyes, nose or mouth, especially after touching a contaminated surface. Germs can easily be spread this way," the news release reported.

Practicing a healthy lifestyle can also make a huge difference in the body's ability to fight infection. This includes getting enough sleep, eating right, and staying hydrated.