Doctors are warning this flu season could be the most dangerous and deadly in many years.
Here in southern California, the flu has already claimed the life of a 51-year-old Fountain Valley man. A south LA clinic, meanwhile, reports that it has been flooded with people sick with the flu.
Massachusetts reported more than 1400 cases in December. That's a jump from just 21 the same month a year ago.
And it's not just the elderly or the very young getting sick. Carly Christenson, a healthy 14-year-old girl from Minnesota, is on life support.
When does the flu require immediate medical attention?
-- When breathing become difficult
-- If there are signs of dehydration including lack of tears or urine
-- If there is blood in the vomit or stool
-- Fever over 104 degrees
Read More: FAQs about the flu