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Seasonal flu resources

Every year, about eight percent of Americans are expected to get influenza (flu). That's a lot, especially since there is a flu vaccine that has a high chance of preventing it.

Every year, about eight percent of Americans are expected to get influenza (flu). That’s a lot, especially since there is a flu vaccine that has a high chance of preventing it.

Flu season can last from October through May, although it peaks between December and February. Getting a flu vaccine is one of the best ways to protect yourself from the flu — all season long.

Flu facts

The flu is a viral infection, like a cold, but flu symptoms will come on suddenly and can lead to bacterial pneumonia, dehydration and worsening of chronic medical conditions. Learning the facts about flu can help you and your loved ones stay healthy.

Flu symptoms
  • Cough
  • Fever or chills
  • Head, muscle or body aches
  • Runny or stuffy nose
  • Sore throat
  • Vomiting and diarrhea (more common in children)
Period of contagiousness
  • Person is exposed to virus
  • Virus has two-day incubation period
  • Person's symptoms appear (A person is contagious one day before and five to seven days after symptoms appear.)
High-risk populations
  • People 65 years old and older
  • People with chronic medical conditions (such as asthma, diabetes or heart disease)
  • Pregnant women
  • Young children

Frequently asked questions about the flu

Below, our medical experts answer common flu questions and provide information on how you can stay well during flu season.

What is the flu and how is it different from the common cold? Is it really that serious?

The flu is very serious. It's a major killer around the world. On the outside, it differs from a cold because of the severity of its symptoms — it leads to high fevers, body aches and respiratory symptoms. Something else that makes the flu really dangerous is while the immune system is busy fighting it off, other issues can sneak in. Many times, when you read about deaths from the flu, they are deaths resulting from bacterial pneumonia that starts after the flu, when your body is already weak.

How do I know if I have the flu or a cold?

Initially when the flu starts, it can seem like a cold — a runny nose and all over “yucky” feeling. But, within a couple of days, it can become a lot worse and bring muscle pains, a spike in fever and coughing. Children (and some adults) with the flu may also have nausea, vomiting and diarrhea.

Use your best judgement and get to the doctor as soon as possible if you suspect you have the flu.

What should I do if I think I have the flu?

See your doctor as soon as possible, especially if you have been around someone with the flu. If you are going to get medication, it needs to be earlier rather than later for it to work properly. Other than that, rest and stay hydrated until it runs its course.

If you can't keep fluids down and feel dehydrated, seek immediate medical care.

How can I protect myself from the flu?

Get the flu vaccine every year. Use other preventive measures such as washing your hands, covering your mouth when you cough and keeping kids home from school if they aren’t feeling well.

How effective is the flu vaccine?

According to the Centers for Disease Control and Prevention (CDC), the vaccine may reduce the risk of flu illness by 60 percent. Most years, the strains that are going around are the ones included in the flu vaccine. But, occasionally, the vaccine is less effective. Even when this happens, the vaccine still provides partial protection and could reduce the severity of the illness.

Is the vaccine only in the form of a shot?

The flu shot is the most effective way to prevent the flu, but there is a nasal spray made of attenuated (weakened) live flu viruses.

Can you get the flu from the flu vaccine?

Absolutely not. If you’re feeling cruddy the next day, yes, that is probably a result of the flu vaccine, but that will be the extent of it.

When is the best time of year to get the flu vaccine?

As soon as it becomes available — usually by the end of August or the beginning of September — before the cold and flu season starts. Usually, the vaccine takes a couple of weeks to become effective.