The Science Behind the Common Cold

There’s a reason they call it the “common cold” — because almost everyone experiences it many times in their lives. On average, adults develop two to three colds per year, according to the Centers for Disease Control. Understanding a bit of the science involved with colds can help you better manage, or even prevent, bothersome symptoms, from coughing and sneezing to congestion and sore throat.

A survey published in Current Medical Research and Opinion in February 2015 took a look at the frequency and duration of the more than 2,500 participants' cough and cold symptoms, the impact the colds had on their daily lives, their treatment preferences and their physiological understanding of colds and coughs. Nearly 70 percent of the participants believed colds were caused by a virus, about 36 percent blamed a weak immune system and about 33 percent credited bacteria. About 15 percent of respondents faulted cold weather, and about half that number said they didn't know the cause at all.

Colds are, in fact, caused by viruses. They are spread from person to person, and you can catch one through direct contact or by ingesting fluid, such as saliva, that contains a cold virus. If someone sneezes near you, for example, you could contract the virus if droplets enter your mouth or nostrils. The virus has to reach the mucus membrane, which lines your eyes, nostrils or mouth, to cause infection. You can also come in contact with the virus indirectly, after touching a doorknob or drinking from the same glass as a person who is infected, for example. While cold weather doesn't directly cause colds, rhinovirus —the most common cause of colds — is better able to reproduce at cooler temperatures.

More than half of respondents of the CMRO survey said that cold symptoms affected their daily lives to a moderate degree or more — 10 percent said severely so. Numerous steps can help lessen these effects. Decongestants can help reduce nasal congestion, says the Cleveland Clinic, though they are not recommended for children unless specifically designed for them. Antihistamines can sometimes manage sneezing and runny noses. Ibuprofen, naproxen, aspirin and acetaminophen help relieve aches and pains, though they may cause stomach upset. Acetaminophen tends to be easier on the stomach than other pain relievers, but larger or continual doses could irritate the liver. If you're allergic to salicylic acids, you should avoid aspirin. Expectorants, such as Mucinex, loosen mucus so it can more easily be expelled. Although more than 25 percent of survey participants said they thought antibiotics were important for treating colds, they do not help treat colds or reduce their symptoms because they work on bacterial, not viral, infections. Resting and staying well-hydrated can help speed healing.

To help prevent your risk of contracting a cold, follow the following list.

• Wash your hands well, particularly after using the restroom, before eating or preparing food and after coming in contact with someone with a cold.
• Regularly clean surface areas in your home and workplace, such as doorknobs, keyboards and faucets, and avoid touching your eyes and nose so
  as not to contract viruses from your hands.
• To strengthen your immune system, eat nutritious foods, exercise regularly and get enough sleep. These measures may not only protect you from colds, but also help lower your chance of spreading the virus to others.