The Family Health Guide

Influenza: How to prevent and treat a serious infection

Influenza: How to prevent and treat a serious infection

It happens every year. The days grow shorter, the temperature drops, footballs fly — and the flu strikes. Influenza is so common that it's easy to dismiss this seasonal affliction as "just a virus" or "just the flu." It's true that the flu is caused by a virus and that most patients recover without specific therapy. But it's also true that thousands of Americans die from the flu each year, and millions are sick enough to miss work or school. Influenza is a serious infection — but it can be prevented and treated.

Up close and personal: Meet the flu bug

Nearly all human flu infections are caused by human strains of the influenza A or B virus. Influenza A is the more serious. It has mastered the nasty trick of disguising itself by changing the proteins on its outer coat. Because of that, people who are immune to an old strain of the flu virus are not protected against new strains. That's why you need to get a new flu shot each year.

Spreading problems

Influenza is highly contagious. As a respiratory virus, it spreads on tiny droplets of mucus that spew into the air when you cough, sneeze, or simply exhale. People close at hand are the most likely to catch the flu, which is why the infection spreads so quickly through families, health care facilities, and other places where people live or work close to each other. The virus can also be spread by hand-to-hand contact.


Influenza hits fast. After an incubation period of just one to two days, the symptoms start abruptly. Most patients are feverish, and high temperatures in the 103° F to 104° F range are common. Nearly everyone has a runny nose and sore throat, but unlike ordinary colds, the flu also produces a hacking, dry cough. Muscle and joint aches can be severe. Headache, burning eyes, weakness, and extreme fatigue add to the misery.

In most cases, the high fever and severe distress settle down in two to five days, but the cough can linger for a week or two and the fatigue even longer.


The most serious — and deadly — complication is pneumonia. Young children, senior citizens, and people with chronic illnesses are at greatest risk, which is why they have the greatest need for preventive vaccinations and medical treatments.

Other flu complications can include asthma attacks, ear infections, bronchitis, sinusitis, inflammation of the heart or other muscles, and inflammation of the nervous system.

Is it the flu?

Allergy Cold Sinusitis Flu
Sneezing Yes Yes No No
Itching eyes or throat Yes No No No
Nasal discharge Watery Watery Thick, discolored Thin
Bad breath or taste in mouth No No Yes No
Facial pain/pressure No Mild Yes No
Fever No Low grade Low to moderate High
Cough No Mild Mild Severe
Muscle aches No Mild Mild Severe
Headache No Mild Mild Severe
Fatigue, weakness No Mild Mild Severe
Fluids No Yes Yes Yes
Inhaled steam No No Yes No
Antihistamines Yes Yes No No
Decongestants Yes Yes Yes Sometimes
Antibiotics No No Yes No
Antivirals No No No Sometimes


Most cases are diagnosed because the season is right, the virus is going around the community, and the symptoms are typical. But milder cases of the flu can resemble other respiratory infections that also strike in the winter. You can use the table above to see if your symptoms are likely to be the flu or a less serious problem — and to start thinking about what to do. And remember to consult your doctor for personal diagnosis and treatment.

Prevention: Hygiene

Whether or not you've had a flu shot this year, a few simple precautions can help protect you and your family:

Wash your hands. Alcohol-based hand rubs and gels are best. Washing your hands for at least 15 seconds with ordinary soap and water will also help. It's not necessary to use very hot water or "antibacterial" soaps.

Keep your distance. The flu is most contagious within three feet of a patient.

Wear a mask if you are in a high-risk group and you can't avoid getting up-close and personal with possible flu victims.

Protect others. Don't go to work or school if you have the flu.

Prevention: Vaccination

New vaccines are produced for every flu season; each protects against the two strains of influenza A and one strain of influenza B that are most likely heading our way in the fall. In the U.S., October and November are the ideal months to get the vaccine. Children ages six months to eight years who have never been immunized need two doses, but one dose will suffice for all others.

Two types of flu vaccine are available. The nasal spray can be used only by healthy, non-pregnant individuals ages 2 to 49. The injectable vaccine can be given to nearly everyone, except people who are allergic to eggs or to the vaccine itself. Side effects are mild and uncommon, amounting to a slightly sore arm or a slight fever.

Immunization can reduce your risk of catching the flu by up to 80%. Here is a list of high-priority vaccine candidates:

  • All children ages six months to four years
  • All adults age 50 and older
  • Children and adolescents ages 6 months to 18 years who receive long-term aspirin therapy
  • Women who are likely to be pregnant during the flu season
  • People who have asthma, diabetes, or chronic diseases of their lungs, heart, blood, kidneys, or liver
  • People who have illnesses or take medications that impair the immune system
  • Residents of chronic-care facilities
  • Health care personnel and child care providers
  • Caregivers and household contacts of persons with medical conditions that put them at risk

Prevention and treatment: Medications

If you get the flu and can start treatment within about 36 hours, ask your doctor about oseltamivir or zanamivir. With or without an antiviral drug, be sure to get lots of rest and drink plenty of fluids. Acetaminophen (Tylenol and other brands) can help ease fever and aches; aspirin is also effective, but should never be used by flu patients under 18 years of age. And be sure to contact your doctor promptly if you think you're developing pneumonia or other complications that may require antibiotics or hospitalization.

November 2008 update

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