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Flu Information

For information on flu vaccination, click here.

PUBLIC HEALTH FACT SHEET: Influenza (Seasonal Flu)

What is flu?
Flu is a disease of the body’s breathing system, including the nose, throat and lungs. Flu is short for “influenza.” Flu is caused by a virus. In New England, the yearly flu season usually begins in the fall and lasts through March. Flu that occurs every winter season is called “seasonal flu.” New and very different flu viruses that appear every 30-40 years, like the H1N1 flu virus in 2009, are called “pandemic flu.” Seasonal flu and pandemic flu have similar symptoms, are spread the same way, and are prevented the same way.

What are the symptoms of flu?
The most common symptoms of flu are fever, cough, and sore throat. Symptoms can also include body aches, headache, chills, runny nose and feeling very tired. Some people, especially young children, also have diarrhea and vomiting. Symptoms last from a few days to up to a week or more.

Is flu serious?
Yes, flu can be very serious. Every year in the U.S. seasonal flu causes thousands of hospital admissions and deaths. Some people are at higher risk of serious health problems when they get the flu. This includes pregnant women, infants, the elderly and people with medical conditions like asthma, diabetes, heart disease, kidney disease, neurological and neuromuscular conditions and weakened immune systems.

How does flu spread?
The flu virus is in the wet spray (droplets of saliva and mucus) that comes out of the nose and mouth of someone who coughs or sneezes. If you are close enough to a person with the flu (3 - 6 feet) when they cough or sneeze, you can breathe in the virus and get sick. Flu symptoms start 1 - 4 days (usually 2 days) after a person breathes in the virus. Flu is spread easily from person to person. The virus can also live for a short time on things you touch like doorknobs, phones and toys. After you touch these objects, you can catch the virus when
you touch your mouth, nose, or eyes. Adults with flu can spread it from about one day before symptoms appear to about one week after. Children can spread the flu even longer after they get sick.

How is flu treated?
There are drugs available that your doctor may prescribe to treat flu. The drugs work best if started soon after symptoms begin. Your doctor can determine if you need treatment. People sick with flu should make sure to drink plenty of fluids, get plenty of rest, eat healthy foods, wash their hands often and stay home to avoid spreading the flu to other people. Over the  counter pain relievers may help people with the flu feel more comfortable. Children and teens with the flu should never take aspirin, because a rare but serious disease called Reye syndrome can occur. Do not give cough or cold medicines to children younger than 4 years of age.

Is there a vaccine for flu?
Yes. A vaccine helps your body to protect itself against a disease. Getting flu vaccine will not give you the flu or any other type of illness. Getting vaccine is the best way to protect yourself against flu.

Who should get flu vaccine?
Everyone 6 months of age and older should be vaccinated for flu. The only exceptions are people with a severe allergy to something in the vaccine. It is especially important that the people listed below get a flu shot every year.
• Children aged 6 months through 18 years
• People 50 years of age and older
• Pregnant and postpartum women
• People of any age with certain chronic medical conditions like asthma, diabetes, heart disease, kidney disease, neurologic and neuromuscular conditions and weakened immune systems
• People with muscle and nerve disorders that make it difficult to breath or swallow
• Children aged 6 months through 18 years on long-term aspirin therapy
• People who live in nursing homes and other long term care facilities
• Anyone who might transmit flu to someone at risk. For example, health care workers, including those in training, emergency response workers, direct care staff, people who live with or care for anyone on the list above, and people who live with or care for infants under 6 months of age, including parents, siblings, and daycare providers

How do I know if I have the flu?
If you have fever with cough or sore throat, you may have the flu. If you think you have the flu, stay home from work and school and avoid contact with others so you do not spread the virus. If you think you might have flu and you need to see your doctor, call ahead and let them know you might have the flu. That way, your doctor’s office can take steps to avoid the spread of flu to others. The doctor may recommend that you be tested for flu.

How can I prevent getting the flu?
• Get flu vaccine every year as soon as it is available.
• Wash your hands often with soap and water, or use an alcohol-based hand gel.
• Cough or sneeze into a tissue or into the inside of your elbow if you don’t have a tissue. Throw tissues away and wash your hands. Always wash your hands before touching your eyes, nose or mouth.
• Use household cleaners to clean things that are touched often, like door knobs, toys, and phones.
• Avoid close physical contact with people who are sick. Try to stay at least 3-6 feet from someone who is sick with the flu.
• People with young children, a weak immune system or a chronic illness should avoid crowds, if possible.
• Stay home from work and school if you get sick with a flu-like illness (fever with cough or sore throat) and avoid contact with others so the virus does not spread. Stay at home until
you have been free from fever for at least 24 hours after your last dose of fever-reducing medication (like Tylenol, Advil or Motrin). For most people this will mean staying at home for
about 4 days.

How do I take care of someone who is sick with flu?
Flu: What You Can Do - Caring for People at Home is available in a comprehensive booklet and a shorter, simpler version. Both are available in many languages and give you information to help you care for someone who has the flu in your home. More information about Flu: What You Can Do can be found at:

Where can I get more information?
• Your doctor, nurse or clinic, or your local board of health (listed in the phone book under local government)
• The Massachusetts Department of Public Health (MDPH), Division of Epidemiology and Immunization at (617) 983-6800 or on the MDPH Website at
• The Centers for Disease Control and Prevention (CDC) website at
• For flu clinic information, please visit: or HealthMap at