Influenza (flu) is an easily spread respiratory tract infection. It is caused by a virus. About 5% to 20% of people in the U.S. get the flu each year. The flu usually starts abruptly, with fever, muscle aches, sore throat, and a cough.
The flu can make people of any age sick. Although most people are sick with the flu for only a few days, some have a much more serious illness. They may need to go to the hospital. The flu can also lead to pneumonia and death.
The flu viruses continually change. Currently, three different influenza viruses circulate worldwide. Vaccines given each year to protect against the flu virus strain expected to cause the illness that year.
The flu is caused by a virus. Viruses are generally passed from person to person through the air when an infected person sneezes or coughs.
But the virus can also live for a short time on objects like doorknobs, pens, pencils, keyboards, phones, and cups or eating utensils. So you can also get the flu by touching something that has been recently handled by someone infected with the virus and then touching your own mouth, nose, or eyes.
Each person may experience symptoms differently. The flu is called a respiratory disease, but it can affect your entire body. People usually become very sick with several, or all, of the following symptoms:
Fever and body aches usually last for 3 to 5 days, but cough and fatigue may last for 2 weeks or more.
The symptoms of the flu may look like other medical problems. Always talk your healthcare provider for a diagnosis.
The flu is diagnosed based on your symptoms. Lab tests may be used to confirm the diagnosis, if necessary.
Specific treatment for the flu will be determined by your healthcare provider based on:
The goal of treatment for the flu is to help prevent or decrease the severity of symptoms. Treatment may include:
Talk with your healthcare provider for more information.
The most common complication of the flu is pneumonia. It can also cause serious muscle and central nervous system complications. Of those who get the flu, between 3,000 and 49,000 will die from it or from complications. Most of these deaths happen in people ages 65 and older.
A new flu vaccine is made each fall. Everyone ages 6 months and older should get a flu shot each year. It is usually recommended for specific groups of people, as well as for anyone who wants to avoid having the flu.
The flu shot is safe. The CDC and the FDA closely watch vaccine safety. Hundreds of millions of flu vaccines have been safely given across the country for decades.
The flu shot can’t give you the flu. The most common side effects from a flu shot are:
If you have them at all, these side effects are usually mild and last a short time.
The effectiveness of the vaccine varies from one person to another. It can depend on factors such as age and overall health.
The following may also be helpful for preventing the flu:
The flu causes complications that may develop into a more serious disease or become dangerous to some people. This includes older adults and those with chronic medical problems. Always talk with your healthcare provider to find out if you should receive the flu shot.
Although the flu shot is safe, some people should NOT be vaccinated. These include:
The CDC recommends getting the flu shot every year, as soon as it becomes available in your community. Flu season can begin as early as October and most commonly peaks in the U.S. in January or February, but flu seasons are unpredictable. The flu shot takes 1 to 2 weeks to become effective.
The CDC recommends that travelers have the flu vaccine at least 2 weeks before planned travel to allow time to develop immunity. Talk with your healthcare provider for more information.
For most people, the flu can be treated at home without treatment from your healthcare provider. However, if your condition or situation makes you more susceptible to complications from the flu, tell your healthcare provider when you suspect you have the flu. If your symptoms get worse or you have new symptoms, let your healthcare provider know.
Tips to help you get the most from a visit to your healthcare provider:
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