'Tis the season -- still -- for that germy double whammy: the common cold and the more-exotic influenza. A cold attacks the airways, its hallmarks a stuffed-up, runny nose, hacking cough and scratchy throat. Influenza mugs the whole body with fever, chills, fatigue, aches and an overall crummy feeling.
Ubiquitous, contagious and incurable, the two have much in common. Both usually last a week or more. They thrive in winter. Both are caused by viruses.
But while some of their symptoms overlap and their names are invoked by some victims almost interchangeably, the common cold and influenza, or flu, are distinct illnesses caused by separate viral "bugs." More than 200 viruses, about half known as rhinoviruses -- from the Greek word for nose -- can cause a cold. An array of shifting viral strains -- classified as A, B or C types and named for the city where they were first identified -- is responsible for the influenza epidemics that annually sweep the globe.
Each year, they make millions of people miserable. Perhaps because they are so widespread and incurable, flu and colds have also given rise to a rich if sometimes-misleading mythology:
Colds and flu are mere nuisances of winter.
Wrong. Influenza can be fatal. It kills 20,000 Americans a year, on average, and sends 200,000 to the hospital.
Flu will afflict between 10 percent and 20 percent of the population this winter. For most, it will mean a week or 10 days of feeling lousy. But in the very young and very old, or those with chronic conditions such as heart or lung disease, flu can lead to serious and even-fatal complications -- primarily pneumonia, which can result when the influenza virus damages the respiratory passageways, allowing bacteria to invade the lungs.
Colds are rarely life-threatening, but their collective toll in misery and absenteeism is nothing to sneeze at. Americans come down with about 1 billion colds a year.
Wear a coat, or you'll catch cold.
Harsh weather alone will not cause flu or the common cold. For either illness to strike, it takes a germ, a virus.
A cold takes hold when the virus reaches the lining of nasal passages, via the eyes, nose or mouth. Colds are spread mainly by touch, kissing or other direct contact -- as when someone with a cold coughs or sneezes in your face. People are most contagious during the first three days of a cold.
The influenza virus is spread mainly by microscopic droplets released into the air by sneezing, coughing, speaking or breathing.
Can I get the flu from a flu shot?
No. The viruses that are used to make the flu vaccine are grown in chicken eggs and then killed by a chemical so that they are no longer infectious.
The most common side effect of a flu shot is a mildly sore arm. In some people, especially children who have not been exposed to the flu, the vaccine can cause flulike symptoms of fever and tiredness for a day or two.
Because flu season usually runs from December through March and it takes four weeks or more to produce maximum protection against the flu virus, the ideal time to get a flu shot is October or early November.
An annual flu shot is recommended for people 65 or older; those with chronic heart, lung or kidney disease, diabetes, anemia or asthma; those living in nursing homes; and health-care workers."The flu vaccine significantly reduces the chance of infection, and even if you do get sick, your symptoms will be much less severe," said Jehan El-Bayoumi, an internist at George Washington University Medical Center.For the common cold, medical science has little to offer in the way of protection. There is no vaccine against cold viruses. The best way to prevent colds is to wash your hands a lot and not get sneezed on.
Starve a cold, feed a fever.
No one knows where that saying came from, or why it caught on. But it's misleading at best, doctors say.
There's no reason not to eat when you have a cold, and there's no reason to force yourself to eat when you're woozy from a flu-caused fever.
The point is: Drink plenty of nonalcoholic fluids, whether you have a cold or a fever. And eat when you feel like it.
Treat a cold and it lasts a week; ignore it and it lasts seven days.
That adage remains largely true.
Nevertheless, medications can lessen discomfort and help get cold sufferers through the night or day. Nonprescription cold remedies, including decongestants, cough suppressants and antihistamines, may relieve symptoms but cannot cure, prevent or shorten a cold. Acetaminophen (Tylenol) is the recommended treatment for headache and general discomfort because it is less likely than aspirin or other nonsteroidal anti-inflammatory drugs to upset the stomach.
Aspirin should not be given to children under 18 because it has been linked to increased risk of Reye's syndrome.
Antibiotics, which fight off bacterial infections, won't do any good against either flu or the common cold, which are caused by viruses. Only complications such as ear infections or pneumonia call for antibiotics.
A pair of antiviral drugs, amantadine (Symmetrel) and rimantadine (Flumadine), can help ward off A-type flu or lessen its severity -- if they are given promptly, within the first day or two after symptoms appear.
Who needs cold medicine when there's vitamin C, Echinacea and Zinc?
Given that colds are perhaps humans' most common illness, it's no surprise that a slew of alternative treatments are touted against them. Among the more popular are extra vitamin C, zinc lozenges and the herbal extract echinacea, which is derived from the purple coneflower.
The good news: They probably won't hurt.
The bad news: There's no conclusive scientific evidence that any so-called alternative treatment prevents or cures the common cold. Timely hand-washing will help more than all of them combined to limit the viral spread, doctors say.
Megadoses of vitamin C, promoted as a cold preventive most famously by the late Nobel laureate Linus Pauling, remain controversial. Despite several large clinical studies, officials from the National Institute of Allergy and Infectious Diseases say, "no conclusive data has shown that large doses of vitamin C prevent colds." Heavy doses of vitamin C can also cause diarrhea.
A scientific review of six studies testing zinc lozenges in patients over the past 15 years reported in November that "the evidence for benefit from treating colds with zinc salts is still lacking." Three of the studies found some lessening of cold symptoms; three found no benefit or worsening symptoms.