Posted on Dec. 19, 2016 ( comments)

Just as everyone has experienced the misery of the common cold, most of us have also experienced the collective “wisdom” passed down through the years about how to cure them or avoid them altogether.

So what’s true and what’s just wishful thinking? We asked our experts to address some common cold beliefs and sort myth from fact.

Here’s what Susan Gustafson, Director of Infection Prevention at MultiCare Health System, and Bruce Oriel, MD, a pediatrician at Mary Bridge Pediatrics, have to say.

Myth #1: I have a really bad sore throat and a fever, so I definitely need an antibiotic.

False.

A sore throat can be caused by a virus or bacteria. If it’s caused by a virus, antibiotics won’t help.

“Fever is simply the immune system fighting the infection, and does not mean it is caused by bacteria,” Dr. Oriel says.

The most common bacterial cause of sore throat is group A strep (strep throat). There is a rapid test for this that’s very accurate, and can provide results in 5–10 minutes. If the strep test is negative, then it typically means a virus is causing the sore throat.

The good news is that the infection will resolve on its own. You can treat symptoms with lozenges, warm tea with honey, salt water gargles and acetaminophen or ibuprofen, Dr. Oriel advises.

Taking unnecessary antibiotics isn’t just a case of overkill, Gustafson says.

“Overuse of antibiotics that are not necessary puts patients at risk of developing antibiotic-resistant bacteria,” she says. “If this happens, we become limited in our ability to treat that infection.”

Antibiotic use is also a risk factor for developing an infection with Clostridium difficile (C. diff), which can cause abdominal pain and diarrhea but can also develop into a much more severe infection.

“We’re seeing C. diff a lot more than we used to, and in people where the only risk factor is that they were on antibiotics,” Gustafson says.

Myth #2: I had a runny nose for a few days and the mucus has turned a really nasty color. Time for antibiotics!

False.

In the past, green or yellow mucus was the justification for giving someone an antibiotic. As a result, antibiotics have been overused, and multiple strains of bacteria have developed a resistance.

“Some of these are now ‘super bugs,’ which are very difficult to treat and may be life-threatening,” says Dr. Oriel.

Instead of signaling the need to call in reinforcements, the color change is a sign your immune system is doing its job.

“The color of the mucus is really just a reflection of the battle that the immune system is waging against the virus or bacteria,” he says.

In fact, any chronic inflammation, such as poorly controlled allergies, can result in thick, colored mucus. Often, when you start noticing the change in mucus, the end of your cold is approaching.

“This is simply the end result of the battle that was waged,” Dr. Oriel says. “If you are starting to feel better, this indicates no need for concern.”

It’s the duration that really matters, not the color.

“If symptoms of heavy nasal drainage and cough are persistent beyond 10–14 days, without improvement, this may indicate a sinus infection,” Dr. Oriel advises.

Additionally, anyone with chest pain or shortness of breath should be seen to make sure they do not have a more serious infection such as pneumonia.

Myth #3: I can prevent or cure a cold with echinacea/zinc/vitamin C.

Debatable.

There are no definitive studies that prove any of these supplements will stop a cold in its tracks. Some studies suggest that taking supplements at the very start of a cold will shorten its duration by a day, but again, nothing definitive.

However, unlike unnecessary antibiotics, there’s not really any harm (except to your wallet) in giving these remedies a try.

The best prevention for colds? Soap and water.

Handwashing is probably the best investment in keeping viruses away, Gustafson says. Stay away from people who are coughing and sneezing, too.

“Droplets can be transmitted for up to six feet,” she says.

Keep your hands away from your face as well. Viruses that cause colds can live on surfaces for hours or days, waiting to hitch a ride on your fingers to your respiratory tract.

Myth #4: I can’t work out/send my kid to soccer practice because of a cold.

False.

As long as you aren’t running a fever or having difficulty breathing, exercise shouldn’t be a problem. Generally, symptoms “above the neck” don’t have to hinder you from exercise if you have the energy.

However, drink lots of fluids and take a break when you start to feel more tired than usual, Dr. Oriel says.

“The immune system is using up energy getting you better,” he says.

Myth #5: My kid went outside wearing shorts in the middle of January. He’ll catch his death of cold!

Probably false.

Dr. Oriel explains the origins of this myth:

“A long time ago, before we knew about microscopic organisms such as bacteria and viruses, we needed to come up with an explanation for why people became sick,” Dr. Oriel says. “Things like exposure to the elements were commonly blamed.”

Now we know that to catch a cold, you have to be exposed to one of the hundreds of viruses known to cause colds. But that doesn’t mean your mother was on the wrong track when she told you to wear your coat.

“In general, going outside in the cold without a coat, or with wet hair, does not make someone ill,” says Dr. Oriel. “But prolonged exposure to harsh elements could weaken the immune system somewhat, making the person more susceptible to illness if they are exposed to an infectious agent.”

Score a half-point for conventional wisdom.

Myth #6: Once you have symptoms, you aren't really contagious anymore.

False.

“A person who still has symptoms of a cold is contagious,” Dr. Oriel says. “We are most contagious in the initial days of the illness, but viruses are very good at what they do — spreading from person to person.”

Gustafson says you may be contagious before you recognize your symptoms, but not before you have them.

“When you first become sick, sometimes it’s gradual,” she says. “At onset you might just have a scratchy throat.”

Once you get sick, it’s best to stay home, cover your cough and stay away from people who are especially vulnerable like newborns or those with chronic heart or lung disease.

After you no longer have a fever and are on the mend, it’s OK to go back to school or work, but continue to cover your coughs and wash your hands frequently.

Cold symptoms? Need to see a doctor? We have options.

This story was originally published in February 2016 and updated in December 2016.