The flu is a serious illness that is often misunderstood and underestimated. Many people describe the flu "like being hit by a truck." Flu symptoms—such as high fever, muscle and joint pain, chills, extreme tiredness and dry cough—strike quickly, are often intense and can leave you in bed for days. Children may have symptoms that are uncommon in adults, including ear infections, diarrhea, vomiting or nausea.

Flu is easy to spread and easy to catch. It is most often spread by coughing and sneezing. When an infected person sneezes or coughs, moisture-infected droplets are released into the air and can travel into your nose and mouth when you breathe. You can infect others starting one day before you notice symptoms and for five days after getting sick.

The most serious, often life-threatening complication of the flu is pneumonia. Other complications include ear infection, bronchitis, dehydration and worsening of chronic conditions, such as congestive heart failure, asthma or diabetes. Croup and a lung disease called bronchiolitis can develop as complications in infants and young children.

The influenza virus changes its genetic make up from year to year, which means that each year you and your family are likely exposed to a new virus. That's why you are at risk of catching the flu every year, and why it is important to get vaccinated annually.

Vaccination is the best way to prevent influenza. The flu vaccine is safe, effective and recommended for most people. Contrary to popular opinion, you cannot get the flu from the flu shot or the newer nasal vaccine. Children getting a flu shot for the first time need two doses given one month apart. While October and November are the best times to get the flu vaccine, it's never too late to get vaccinated.

Prescription antiviral medications are an important partner to vaccine in fighting the flu. Antiviral medications—such as oseltamivir (Tamiflu) or zanamivir (Relenza)—can be prescribed by your doctor to help treat and prevent the flu. Tamiflu is taken orally and is available in capsule or liquid form. Relenza is inhaled by mouth using an inhalant device.

It is crucial to contact the health care professional at the first signs of flu symptoms. If you or your child is experiencing flu symptoms, a health care professional can prescribe antivirals to help you feel better faster. However, it's important to contact a health care professional fast, because antiviral medication must be taken within 12 to 48 hours of symptom onset.

If you or your child has been around someone who has the flu, a health care professional can also prescribe antiviral medication to help prevent the flu from spreading in your family. Again, speed is critical, and antiviral medication should be taken within the first 12 to 48 hours of exposure to the virus. When administered within 48 hours of exposure, Tamiflu is up to 92 percent effective at preventing flu in adults, and 82 percent effective in preventing flu in children. And, while they don't make it go away overnight, these medications can help you feel better a day or two sooner than if you didn't take the medicine.

Simple good hygiene measures can help reduce your family's likelihood of getting sick. Parents should teach their children healthy habits such as:

• washing their hands frequently with soap and warm water for at least 20 seconds
• covering their mouths and noses with tissues when sneezing and coughing
• avoid sharing drinks, water bottles, silverware and pencils

Children experiencing flu symptoms should always stay home from school. Close contact with others in the school, home and day-care settings increases children's risk of contracting and spreading the flu virus. Therefore it's important to keep your child home when sick. If your child has a cold, the decision to keep him or her home may depend on the severity of symptoms. A good rule of thumb is to keep your child home if he or she has a fever of 100 degrees or higher.

Flu outbreaks can happen in day care and school settings. Influenza outbreaks sweep quickly through a community, affecting approximately five to 20 percent of Americans annually, although rates of infection vary among age groups and from one season to another. Talk to your child's day care or school to find out whether there are protocols in place if there is a flu outbreak.