Influenza, or "flu," is caused by a virus infecting the respiratory system, meaning your nose, throat, bronchial tubes, and lungs. Flu symptoms are usually more severe than those of the common cold and are more likely to affect other parts of your body. Flu also tends to come on suddenly while colds can develop gradually.
Flu is very contagious, spreading easily from one person to the next. Most people with healthy immune systems will get over the flu within 2 weeks, but young children, older adults, and people with chronic illnesses are more likely to develop complications such as pneumonia. About 35,000 people die of flu each year in the United States.
There are three types of flu viruses: A, B, and C. Type A viruses are the ones responsible for worldwide epidemics, such as the one in 1918 that killed as many as 50 million people worldwide. The avian or bird flu is a type A flu virus.
The best way to protect yourself from the flu is to get an annual vaccine (flu shot).
Signs and Symptoms
Influenza is caused by viruses that are spread through the air by sneezes and coughs, or by touching a surface a person with the flu has touched and transmitting the virus to your mouth or nose. Some flu viruses cause a very mild illness, or none at all. Others cause serious, widespread illness.
Since there are many types of influenza virus, and because they change over time, scientists develop a new flu vaccine every fall. Getting vaccinated before the flu season starts reduces your chances of getting the flu and helps you recover faster if you do get it. You should not take the vaccine if you have a severe allergy to eggs because the viruses for the vaccines are grown in chick embryos. See Risk Factors for list of people who should get the vaccine every year.
Infants and young children, as well as senior adults, are considered at highest risk of complications from flu. Other risks include:
If you are at risk for complications, you should get an annual flu shot (see Preventive Care).
Your doctor will probably be able to diagnose flu from a physical exam and a description of your symptoms. Your doctor may take a chest x-ray if there is concern about complications such as pneumonia.
The best way to prevent the flu is by getting a flu shot. Annual flu shots are recommended if you:
You should not receive the vaccine if you are severely allergic to eggs.
You can also cut your risk of flu by washing your hands frequently during flu season. In one study, using alcohol-based sanitizer, along with good respiratory hygiene, reduced school absences by 26% and laboratory confirmed influenza A infections by 52%.
Bed rest and drinking plenty of fluids are usually enough to treat flu. Mild over-the-counter pain relievers and fever reducers (such as acetaminophen, or Tylenol, and ibuprofen, or Advil), can help relieve fever and muscle aches. If you are at high risk for complications (see Risk Factors), then your doctor may prescribe antiviral medications, drugs that fight the virus. They must be started within 2 days to be effective. Studies show that taking antiviral medications within 2 days of the onset of symptoms may reduce the duration of the illness by a day. Certain herbs, supplements, and homeopathic remedies may help relieve symptoms.
Antiviral medications. Several antiviral medications have been approved by the Food and Drug Administration (FDA) to treat flu. However, a number of flu viruses have developed resistance to some of the medications. In addition, using these medications may help contribute to other strains of flu becoming resistant. These drugs must be started within 48 hours of becoming sick to be effective. Medications include:
Nutrition and Dietary Supplements
Because supplements may have side effects or interact with medications, you should take them only under the supervision of a knowledgeable health care provider. Be sure to talk to your doctor about any supplements you are taking or considering taking.
The use of herbs is a time-honored approach to strengthening the body and treating disease. Herbs, however, can trigger side effects and can interact with other herbs, supplements, or medications. For these reasons, you should take herbs with care, under the supervision of a health care practitioner. Before giving any herbs to a child to treat the flu, talk to your pediatrician.
Although very few studies have examined the effectiveness of specific homeopathic therapies, professional homeopaths may consider the following remedies for the treatment of the flu based on their knowledge and experience. Before prescribing a remedy, homeopaths take into account a person's constitutional type. A constitutional type is defined as a person's physical, emotional, and psychological makeup. An experienced homeopath assesses all of these factors when determining the most appropriate treatment for each individual.
Warnings and Precautions
If you are in any of the high risk groups described in the Risk Factors section, be sure to call your doctor at the earliest signs of flu symptoms. The sooner you are treated, the less likely you are to develop complications.
Prognosis and Complications
Most healthy people get over the flu in within 2 weeks. For those at high risk, certain serious, even life threatening complications can occur, including:
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Review Date: 9/29/2015
Reviewed By: Steven D. Ehrlich, NMD, Solutions Acupuncture, a private practice specializing in complementary and alternative medicine, Phoenix, AZ. Review provided by VeriMed Healthcare Network. Also reviewed by the A.D.A.M. Editorial team.
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