Flu Basics

About the flu

Influenza, commonly called the "flu", is a contagious respiratory illness caused by influenza viruses. It can cause mild to severe illness and, at times, can lead to death. Although most healthy people recover from the flu without complications, some people, such as older people, young children, and people with certain health conditions, are at high risk for serious complications from the flu.

How do I know if I have it?

Influenza usually starts suddenly and may include the following symptoms, some of which are also signs of the common cold:

• Fever (usually above 101 degrees)
• Headache
• Tiredness (can be extreme)
• Cough
• Sore throat
• Stuffy nose
• Body aches
• Diarrhea and vomiting (more common among children than adults)

However, if you experience these symptoms but do not experience respiratory symptoms, it is unlikely that you have the flu.

What are the risks?

In some people, the flu can cause serious complications, including bacterial pneumonia, dehydration, and worsening of chronic medical condition such as congestive heart failure, asthma, or diabetes. Children and adults may develop sinus problems and ear infections

How is the flu spread?

The flu usually spreads from person to person in respiratory droplets when people who are infected cough or sneeze. Touching something with influenza virus on it and then touching their mouth, nose, or eyes occasionally may infect people. Healthy adults may be able to infect others 1 day before getting symptoms and up to 5 days after getting sick. Therefore, it is possible to give someone the flu before you know you are sick as well as while you are sick.

How can we avoid spreading the flu?

Some simple hygienic behaviors that can help prevent the spread of respiratory illnesses such as the flu are:

• Cover your nose and mouth with a tissue when you cough or sneeze—throw the tissue away after you use it.
• Wash your hands often with soap and water, especially after you cough or sneeze. If you are not near water, use an alcohol-based hand cleaner.
• Avoid close contact with people who are sick. When you are sick, keep your distance from others to protect them from getting sick too.
• If you get the flu, stay home from work, school, and social gatherings. In this way you will help prevent others from catching your illness.
• Try not to touch your eyes, nose, or mouth. Germs often spread this way.

What about the flu vaccine?

The best way to protect yourself and others against influenza is to get a flu vaccination each year. Two kinds of flu vaccine are available:

• The "flu shot"—an inactivated vaccine (containing killed virus) that is given with a needle, usually in the arm. The flu shot is approved for use in people older than 6 months, including healthy people and people with chronic medical conditions.
• The nasal-spray flu vaccine—a vaccine made with live, weakened flu viruses that do not cause the flu (sometimes called LAIV for “live attenuated influenza vaccine”). LAIV is approved for use in healthy people 2 years to 49 years of age who are not pregnant.

October or November is the best time to get vaccinated, but you can still get vaccinated in December and later. Flu season can begin as early as October and last as late as springtime.

What is the flu shot?

The flu shot is an inactivated vaccine (containing killed virus) that is given with a needle, usually in the arm. It contains three influenza viruses. It contains three influenza viruses which are representative of the influenza vaccine strains recommended for that year. The three vaccine strains – one A (H3N2) virus, one A (H1N1) virus, and one B virus – are representative of the influenza vaccine strains recommended for tha year. Viruses for the flu shot are grown in eggs.

Who shoud get a flu shot?

In general, anyone who wants to reduce their chances of getting the seasonal flu can get a flu shot. However, there are people who are at high risk for developing serious complications from the flu or people who live with or care for those who are at high risk for flu complications.

Persons who should be especially concerned about being vaccinated are:

• All children aged 6 months to five years old, Adults aged 50 years of age or older,
• Persons aged 5-49 years with underlying chronic medical conditions,
• All women who will be pregnant during influenza season,
• Residents of nursing homes and long-term care facilities,
• Children 6 months-18 years of age on chronic aspirin therapy,
• All health care workers,
• Out-of-home caregivers and household contacts of children less than six months old, and
• Any persons who would like to reduce their risk of contracting influenza.

Pneumonia Vaccine

People over age 65 and those with chronic medical conditions such as heart disease and diabetes should discuss obtaining pneumonia vaccine with their physicians. The vaccine is effective in preventing many types of pneumonia, the major complication from influenza.

What should I do if I get sick?

It is very difficult to distinguish the flu from other infections on the basis of symptoms alone. A doctor's exam may be needed to tell whether you have developed the flu or a complication of the flu. There are tests that can determine if you have the flu as long you are tested within the first 2 or 3 days of illness.

If you develop flu-like symptoms and are concerned about your illness, especially if are at high risk for complications of the flu, you should consult your health-care provider. Those at high risk for complications include people 65 years or older, people with chronic medical conditions, pregnant women, and young children.

If you get the flu, get plenty of rest, drink a lot of liquids, and avoid using alcohol and tobacco. Also, you can take medications such as acetaminophen (e.g., Tylenol¨) to relieve the fever and muscle aches associated with the flu. Never give aspirin to children or teenagers who have flu-like symptoms, particularly fever.

Click here to learn more about seasonal flu and pandemic flu.