Influenza - "the flu"

What is influenza?

Influenza is a respiratory (nose, throat, lungs) illness caused by influenza viruses (germs). Commonly known as the "flu," influenza can cause mild to severe illness.

Each year, about 5 to 20 percent of people in the U.S. will get influenza. It causes about 36,000 deaths and more than 200,000 hospital stays in the U.S. each year. The flu season usually lasts from late December through March.

Influenza is not the "stomach flu." Vomiting, nausea and diarrhea are caused by other bacteria or viruses and are rarely related to influenza.

Who can get influenza?

Anyone can get influenza. Older people, very young children, and people of any age with certain health conditions are at the greatest risk for serious complications (problems) of the flu.

How is influenza spread?

Influenza is mainly spread from person to person through coughing and sneezing by an infected person.

What are the symptoms of influenza?

Symptoms include: fever (usually high), extreme tiredness, headache, sore throat, runny or stuffy nose, dry cough and muscle aches.

Nausea, vomiting and diarrhea can also occur, but these symptoms are more common in children than in adults.

Symptoms appear 1 to 4 days after exposure to the virus. The average is about 2 days.

How is influenza found?

Your health care provider can tell if you have influenza during an exam.

A swab of your nose secretions can confirm influenza if it is done within the first 2 to 3 days after symptoms begin.

How is influenza treated?

Your health care provider will suggest treatment for your symptoms.

What are the complications of influenza?

Complications (problems) of influenza can include:

ear infections
sinus infections (sinusitis)
bacterial pneumonia
dehydration
worsening of existing conditions, such as asthma, congestive heart failure or diabetes (type 2)

How long can the germ be spread?

Most healthy adults can spread influenza to others beginning 1 day before becoming sick and up to 5 days after becoming sick. Children may spread the virus for longer than 1 week.

How can you protect yourself?

The best way to prevent influenza is to get a flu vaccination each year. There are 2 types of vaccines offered each fall.

The "flu shot" is made from inactive (killed) flu viruses that is given with a needle. This vaccine is approved for people older than 6 months, including healthy people and people with chronic (long-lasting) health conditions.
Nasal-spray flu vaccine is made with live, weakened flu viruses. This vaccine is approved for healthy people 2 years to 49 years of age who are not pregnant.

In general, vaccination is recommended for:

people who are at the greatest risk for serious complications (problems) of the flu, including:

adults age 50 or older
children age 6 months until their 5th birthday
women who are pregnant during the flu season
residents of a nursing home or group residential facility
anyone older than 6 months who has heart or lung conditions (including asthma), who needs regular medical care or has a weakened immune system
children ages 6 months to 18 years who are on long-term aspirin therapy

people who live with or care for those who are at the greatest risk for serious complications (problems) of the flu, including:

care givers for children less than 6 months of age
health care workers

Talk with your health care provider before getting a vaccination if you:

have a severe allergy to eggs
had a reaction to the influenza vaccine in the past
developed Guillain-Barré syndrome in the 6 weeks after getting the vaccine

Vaccines do not cause the flu. They only protect you from the influenza virus. You can still get sick with different viruses which cause a respiratory illness.

You need to get a vaccination every year because new strains of the influenza virus are always circulating. The vaccine is updated every year to include the different strains. It takes about 2 weeks after the shot for the antibodies to develop in your body to give protection. You are at risk for getting the flu during these 2 weeks.

What prevents the spread of the germ?

To keep the influenza virus from spreading, take these steps:

Cover your mouth and nose with a tissue when you cough or sneeze.
Avoid touching your eyes, nose or mouth.
Wash your hands often with soap and water or a waterless alcohol hand sanitizer.
Avoid close contact with anyone who has the flu. If you get the flu, keep your distance from others to protect them from getting sick too.
Stay home from work or school if you have the flu until the symptoms are gone.
Practice other good health habits: eat well-balanced meals, exercise, manage your stress, drink plenty of fluids and get plenty of rest.