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Colds: How to Prevent Them

  • Viral infections of the upper respiratory tract
  • Symptoms include stuffy or runny nose, cough, low fever, sneezing, sore throat, and general aching
  • There is no cure for colds—only treatment of symptoms, which can last from two days to two weeks
  • Involves Infectious Diseases, Laboratory Medicine

Colds: How to Prevent Them


The common cold is one of the most stubborn challenges in health care, but Yale Medicine is working on finding better solutions. 

While there is much about the common cold that we know already—like its telltale symptoms of stuffy or runny nose, cough, low fever, sneezing, sore throat and general aching—there is plenty that we are still discovering, says Ellen Foxman, MD, PhD, a Yale Medicine medical researcher and clinical pathologist. Along with other Yale colleagues, Dr. Foxman is investigating the natural defenses that our bodies use to fight off infection with cold-causing viruses. 

What causes a cold?

The common cold is probably the most universal illness. Adults catch an average of 2-3 colds each year, and children usually have even more. What we refer to as the “common cold” is a viral infection of the upper-respiratory tract, meaning the nose and throat area.

"Several viruses can potentially cause a cold, but rhinoviruses are most often to blame," says Dr. Foxman. Therefore, understanding rhinovirus—of which there are more than 100 known varieties—is key to conquering the common cold. Rhinovirus can also lead to other respiratory ailments. For example, it is a major trigger of asthma attacks.

Rhinovirus spreads from person to person. People most often pick it up by touching their faces after coming into contact with surfaces where the virus is present.

"Viruses are little germs that get into your nose, and they can make you sick if they find the opportunity to grow," Dr. Foxman says. "Yet recently one interesting finding is that a lot of us are getting the cold-causing virus without actually getting sick—up to 20 percent of us."

Why can’t we cure the common cold?

There is no cure for colds; there only is treatment of symptoms, which can last anywhere from two days to two weeks.

"Rhinovirus mutates very quickly and comes in many varieties, and for this reason, doctors are unable to make a vaccine to fight off colds as we can for the flu," says Dr. Foxman. 

Antibiotics do not work against colds because they kill bacteria, not viruses, Dr. Foxman says, so there is no reason to use them for a cold. This is especially important to know at a time when overuse of antibiotics has become a major concern because of increased antibiotic resistance. Unnecessary use of antibiotics may also harm your individual health.  

"There is a lot of research that shows when you take antibiotics, you may be wiping out good, health-promoting bacteria as well as the bad bacteria," Dr. Foxman says.

Relief for the common cold is found through resting, increasing intake of fluids, gargling with warm salt water and possibly taking over-the-counter cold medicines, such as decongestants or cough suppressants.

There's still much about colds we don't know, Dr. Foxman says. "If we understand the natural defense mechanisms that keep us from getting sick, we can better suppress colds. This is what we're working towards."

What has Yale Medicine learned about preventing colds?

Yale Medicine is tied to a world-class university, where top-notch scientists are performing research that can fill in gaps that remain in our understanding of illnesses such as the common cold.

Before it can cause illness, rhinovirus or other cold-causing germs first have to find their way into the nose or mouth. Next, rhinovirus enters the cells that form the lining of the airway and makes copies of itself, which leads to illness. 

The scientists found that rhinovirus grows better at cooler temperatures because natural anti-viral defenses in these cells do not work as well. At cooler temperatures, the sensors in cells that detect viruses dull a bit, and they fail to alert other cells to produce protective antiviral proteins. Those findings fit with conventional wisdom that inhaling cold air may increase the likelihood of developing a cold.

Researchers are also pushing for more advanced tools to combat respiratory infections. “There are tests we don't now have that, if we could develop them, would be helpful to guide patient care,” Dr. Foxman says.

“Having more people accept and understand the idea that an antibiotic isn’t always the immediate answer would be a great thing,” says Dr. Foxman.