Learn how immunizing a critical portion of a community protects most members of the community.
Symptoms and Complications
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People who have the flu often experience
Signs of Emergency
Certain symptoms of the flu may signal an emergency and should be assessed by a medical professional.
In children, these include
In infants, additional symptoms that could signal an emergency include
In adults, watch out for
Severity of Flu
Flu is unpredictable. Its severity can vary widely from one season to the next depending on many factors, including
One study found that during the 1990s, flu-related deaths in the United States ranged from an estimated 17,000 during the mildest season to 52,000 during the most severe season, averaging 36,000 per year. Over a period of 31 flu seasons between 1976 and 2007, estimates of flu-associated deaths in the United States ranged from a low of about 3,000 to a high of about 49,000 people. During a typical flu season, about 90 percent of deaths occur in people age 65 and older.
Complications From the Flu
Most people who get influenza will recover in less than two weeks, but some people will develop complications, some of which can be life-threatening or fatal. Complications can include bacterial pneumonia, ear or sinus infections, dehydration, and worsening of chronic medical conditions, such as congestive heart failure, asthma, or diabetes.
Complications usually appear after a person starts feeling better. After a brief period of improvement, the following symptoms may suddenly appear:
Reye's syndrome, a condition that affects the nerves, sometimes develops in children and teens who are recovering from the flu. Reye's syndrome begins with nausea and vomiting, but the progressive mental changes, such as confusion or delirium, cause the greatest concern.
The syndrome often begins in young people after they take aspirin to reduce fever or pain. Acetaminophen does not seem to be connected with Reye's syndrome.
Who Is at Risk?
Certain people are at greater risk for serious complications if they get the flu. These groups include
Last Updated November 14, 2012
Last Reviewed November 14, 2012