Cold and Flu IQ

Our guide to the most common misconceptions about what causes colds and flu's -- and how to prevent and treat them.

Reviewed by Michael W. Smith, MD on January 04, 2011
From the WebMD Archives

When it comes to what the average person believes about colds, there seems to be as many misconceptions as cold medicines on a drugstore shelf. And now that the winter cold and flu season is in full swing, we turned to Thomas Tallman, DO, an emergency medicine physician and cold and flu expert at the Cleveland Clinic, to set us -- and you -- straight on prevention and treatment.

Do You Catch Cold Because Your Immunity Is Low?

Cold viruses do not require a weakened immune system. The most common cold-related myth, Tallman says, is that colds strike only those whose immune systems are not running at full capacity. That is simply not true, he says. "You can be healthy as an ox and still get a cold."

Do Vitamin C and Zinc Prevent Colds?

Vitamin C and zinc probably don't keep colds at bay. When threatened with a cold, Tallman says, "people reach for the vitamin C or zinc. While some studies suggest these supplements might help shorten cold symptoms, others show they don't. Tallman doesn't think there's enough evidence to support their use, and the National Center for Complementary and Alternative Medicine, a division of the NIH, concurs.

Does Dry or Cold Air Cause Colds?

Dry air does not cause colds. Many people believe that hot, dry air can dry up the mucus in your nasal passages, leaving you more susceptible to colds. Not true, says Tallman. As far as colds are concerned, he says, "It doesn't matter what the humidity is." If you are already sick, though, moist air can help ease congestion and coughing, making your suffering a bit more bearable.

Cold weather also does not cause colds -- at least not directly. Despite its name, the common cold is not caused by cold. "It doesn't have any effect at all," says Tallman. "There's no correlation." In fact, you may be more likely to "catch your death of cold" indoors, where it's warm and crowded than outdoors in the chilly air. People in close quarters are more readily exposed to carriers of the viruses that cause colds. "If one person in a household gets sick, it will spread easily," Tallman says.

Do Antibiotics Cure Colds?

Antibiotics are not the answer to the common cold. These drugs target bacteria; they cannot kill the viruses that cause colds. In fact, they can do harm. The more you take antibiotics, the more your body develops natural resistances, making them less effective when you really need their healing power. Tallman says it's not uncommon to see parents in the emergency room who want antibiotics for their child's cold or flu. That's a mistake. "Antibiotics are a no-no," says Tallman. "They are not effective with colds."

Will I Get the Flu from a Flu Shot?

The flu vaccine does not cause the flu. "You won't get sick from it," Tallman says. However, it is possible that some people who get vaccinated for the flu develop flu-like symptoms, such as aches or a fever -- but only for a day or so. That's a small price to pay for a vaccine that prevents an average of five days of fever, headaches, sore throat, and other symptoms caused by actual flu, which can also cause complications such as pneumonia. Those who are most vulnerable to such complications include anyone over the age of 65, pregnant women, and people with pre-existing conditions like asthma, chronic lung disease, heart disease, diabetes, and weakened immune systems.

Should I Starve a Cold?

Starve a cold and feed a fever? Or is it the other way around? The answer: neither. Tallman's not sure where this erroneous piece of advice originated, but he is sure of this: What you eat when you have a virus makes no difference in the length or severity of your cold. He does recommend you drink a lot of fluids while you are sick to avoid becoming dehydrated. And he refutes a related myth, that drinking milk increases the mucus in your nasal passages. "It has no effect," Tallman says.

Home Cough Remedies

Look to your pantry to calm a cough. Maybe Grandma's shot of whiskey or hot toddy won't help a cough, but you've probably got some items on hand that will. Tallman mentions onion and garlic juice, lemon juice, cloves, and ginger. Coughs that accompany a sore throat and sinus trouble respond well to soothing treatments such as hot tea and honey, he says. "It would be difficult to debunk honey as a cough suppressant. The bottom line is people use whatever they think provides symptomatic relief." (However, never give honey to children younger than age 1.)

A Cure for the Common Cold?

There's no cure for the common cold. This is not a myth, just a reminder. Cold medications can only relieve symptoms, not speed up recovery. As Tallman says, "There's nothing you can do but ride it out." You can take measures to ward off colds, however. Keeping your hands clean is one of the most effective ways to prevent germs from spreading. If you want to avoid the flu, your best bet is to get the vaccine.

Not everyone can be cured of false beliefs. Alas, this is not a myth either. Tallman says his approach when talking to a misinformed patient is to say, "That's silly, and let me tell you why." Is he convincing? Only about 50% of the time, he says. "Half will at least look at things differently after I talk to them."

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Tom Tallman, DO, Cleveland Clinic, Cleveland, Ohio.

National Center for Complementary and Alternative Medicine: "Cold and Flu and CAM: At a Glance."

Mayo Clinic: "Common Cold."

CDC: "Get Smart: Common Cold and Runny Nose."

CDC: "Seasonal Influenza (Flu): Key Facts about Influenza (Flu) & Flu Vaccine."

National Institute of Allergy and Infectious Diseases: "Common Cold: Prevention."

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