(Source: National Institutes of Health, www.nih.gov
What is influenza and what causes it?
Influenza, or the flu, is a respiratory infection caused by a variety of flu viruses that are airborne. The flu differs in several ways from the common cold, a respiratory infection also caused by viruses. Although flu symptoms are felt throughout the body, the flu virus lives and multiplies primarily in the lungs. People with colds rarely get fevers or headaches or suffer from the extreme exhaustion that flu viruses cause. Flu season typically lasts from November to March.
How does it occur?
You can get the flu if someone around you who has the flu coughs or sneezes. You can get the flu simply by touching a surface like a telephone or door knob that has been contaminated by a touch from someone who has the flu. The viruses can pass through the air and enter your body through your nose or mouth. If you've touched a contaminated surface, they can pass from your hand to your nose or mouth. You are at greatest risk of getting infected in highly populated areas, such as in crowded living conditions and in schools.
What are the symptoms?
- Body aches
- Dry cough
- Sore throat
- Stuffy nose
- Loss of appetite
- Upset stomach, diarrhea, and vomiting are not symptoms of the flu—"stomach flu" is usually caused by other microorganisms and is often mistakenly referred to as the "flu".
- If you get infected by the flu virus, you will usually feel symptoms 1 to 4 days later. You can spread the flu to others before your symptoms start and for another 3 to 4 days after your symptoms appear. Typically, the fever begins to decline on the second or third day of the illness.
How is it diagnosed?
Usually, the flu is diagnosed on the basis of whether it is epidemic in the community and whether your complaints fit the current pattern of symptoms. Laboratory tests are rarely used to identify the virus during an epidemic.
How is it treated?
- Resting in bed
- Drinking plenty of fluids
- Taking over the counter medicine such as acetaminophen (Tylenol)
- Antibiotics are not used to treat the flu because they do not work on viruses.
Things that may help prevent the flu
The main way to keep from getting the flu is to get a yearly flu vaccine. Your immune system takes time to respond to the flu vaccine. Therefore, you should get vaccinated 6 to 8 weeks before flu season begins to prevent getting infected or reduce the severity of the flu if you do get it. The vaccine itself cannot cause the flu, but you could become exposed to the virus by someone else and get infected soon after you are vaccinated. Some possible side effects from the flu vaccine are soreness at the site of vaccination, sore muscles, and a slight fever. These side effects may begin 6 to 12 hours after vaccination and may last for up to 2 days. The flu vaccine is contraindicated if you have an allergy to eggs.
Reasons to call the health center
- High fever
- Shaking chills
- Chest pain with each breath
- Coughing that produces thick, yellow-greenish colored mucus