Influenza, commonly called "the flu", is an infection of the respiratory tract (nose, throat, airways, and lungs) caused by the influenza virus. Two types of influenza virus, A and B, cause the flu. Although flu is similar in some ways to the common cold, it begins suddenly and symptoms are much more severe than those of a cold.
What are the symptoms of the flu?
The incubation period from time of exposure to the onset of symptoms ranges from 1-4 days. Symptoms usually begin suddenly with high temperature (100 degrees or more), muscle aches, headache, dry cough, and weakness. Sore throat and stuffy nose also may occur. Severe symptoms including fever often last for 3 to 5 days and symptoms such as cough, weakness, and fatigue may persist for several weeks.
Nausea, vomiting, and diarrhea are uncommon in adults with the flu. The term "stomach flu" is incorrectly used referring to these symptoms, since this is not influenza.
The influenza virus is very contagious and easily spread from infected persons to others around them. Most commonly when a person with the flu coughs or sneezes, tiny droplets of moisture containing the virus are released into the air to infect others. A person with the flu continues to be infectious for 3 to 4 days after symptoms begin. People with the flu should cover their mouths and noses with a tissue when coughing or sneezing to reduce the number of infectious droplets they release into the air.
Quick, accurate, and inexpensive laboratory tests to diagnose the flu are not readily available. Although symptoms similar to influenza can be caused by other infections, most people with the sudden onset of fever, muscle aches, headache, and dry cough during a community outbreak of influenza do, in fact, have the flu.
Can I avoid getting the flu? Where can I get vaccinated?
The most effective way of preventing the flu is getting the influenza vaccine each year. Vaccination prevents 70-90% of infections in healthy young adults. It takes up to 2 weeks after vaccination to develop immunity, so it's best to get vaccinated before flu season begins. Vaccination is strongly recommended for everyone at increased risk of influenza complications including those with underlying heart or lung problems including asthma, other chronic medical conditions that may interfere with immunity including diabetes, and those over age 65.
Other practices which strengthen your immune system also reduce your risk of catching the flu. It is important to get enough rest, drink plenty of liquids, eat nutritious meals, exercise moderately, and avoid immune system depressants such as tobacco and alcohol. Washing your hands frequently may also reduce your exposure to the virus.
Rest is very important. Stay home, both to rest and to avoid exposing others, and drink lots of liquids (water, sports drinks, broth, tea, etc.) to strengthen your immune system and avoid dehydration.
Medications such as acetominophen (Tylenol) or ibuprofen (Advil) may help to reduce fever, muscle aches, and headache. Cough medicine, salt water gargles (1/4 tsp salt per cup of water) for sore throat, and nasal decongestants are helpful for symptomatic relief.
Antibiotics have no effect on the flu. Influenza is a viral infection and antibiotics work only against bacterial infections.
Prescription antiviral medications such as amantadine, rimantadine, and a new class of drugs called neuraminidase inhibitors can decrease the duration of severe flu symtoms by about 1 day if started within 48 hours of symptom onset.
What are the complications of the flu?
Just about everyone who catches the flu feels really lousy and sick for several days, but just about everyone also recovers fully with rest and symptomatic treatment. A small percentage of people with the flu develop complications which may be serious. These include pneumonia, secondary bacterial sinus and ear infections, and worsening of underlying medical problems such as asthma and diabetes.
Should I see a doctor if I have the flu?
If you are sure that you have the flu it is reasonable to rest at home and take symptomatic medication as needed.
If you have an underlying medical problem such as asthma or diabetes which affects your ability to fight off or recover from infection you should make an appointment to be seen at the Health Center.
Who should NOT get a flu shot without consulting their physician?
For more information, go to http://www.cdc.gov/flu
- People who have a severe allergy to chicken eggs.
- People who have had a severe reaction to an influenza vaccination in the past.
- People who developed Guillain-Barré syndrome (GBS) within 6 weeks of getting an influenza vaccine previously.
- Children less than 6 months of age (influenza vaccine is not approved for use in this age group).
- People who have a moderate or severe illness with a fever should wait to get vaccinated until their symptoms lessen.
Call your Family Physician if you have the flu and:
- a fever over 100 degrees for more than 5 days
- a cough which brings up discolored or bloody mucus
- chest pain or shortness of breath
- severe facial pain or earache
- symptoms that don't get better over 7 days or get worse again after getting better
As much as we’ve tried to think of any question you might have and to answer it somewhere on this site, we realize that there may be some questions that aren’t addressed on this site.
If you have any general questions about the program that we haven’t answered, please ask/call your supervisor. For medical questions, call your family doctor or the Centers for Disease Control and Prevention (1-800-232-4636). Don’t let an unanswered question prevent you from benefiting from this program.