The flu season is upon us, and once again it's time to be on the lookout for flu symptoms.

Various strains of contagious influenza viruses will soon get passed around through coughs, sneezes and other methods of contamination.

The Centers for Disease Control and Prevention (CDC) recommends getting a flu vaccine each year, particularly for the people most at risk, which includes children under 5 years of age, seniors over 65 and people with certain medical conditions like asthma, chronic lung disease and weakened immune systems. As always, washing your hands may be the single best way to avoid getting the flu. (Read more: Flu vaccine side effects)

Symptoms of influenza include:

  • Fever/chills
  • Cough
  • Sore throat
  • Runny or stuffy nose
  • Muscle or body aches
  • Headaches
  • Fatigue
  • Vomiting and diarrhea (more common in children)
Flu outbreaks can happen as early as October, but peak activity is typically seen in mid-winter. If you believe you have the flu, you should stay home for at least 24 hours after your fever is gone and avoid social interaction to prevent spreading it to others.

While most flu illness is mild and doesn't require medical attention, some warning signs should instigate immediate action, including:

  • Difficulty breathing, shortness of breath
  • Pain or pressure in the chest or abdomen
  • Sudden dizziness
  • Confusion
  • Severe or persistent vomiting
  • Flu-like symptoms that improve, but return with a fever and more severe cough
In children, look for the following:
  • Fast breathing
  • Bluish skin color
  • Not drinking enough fluids
  • Not waking up or not interacting
  • Severe irritability/child does not want to be held
  • Flu-like symptoms that improve, but return with a fever and more severe cough
  • Fever with a rash
The CDC says that while the flu season is unpredictable and there's always a possibility for new strains to emerge, the 2012 season is off to an early start. (You can keep up with updates on the flu season at this handy CDC flu website.)

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