A cold is an upper respiratory infection caused by any one of hundreds of different viruses. Unfortunately, scientists haven't figured out how to wipe out these viruses. The body has to rely on its own natural defenses.
During a cold, virus particles penetrate the mucous layer of the nose and throat and attach themselves to cells there. The viruses punch holes in the cell membranes, allowing viral genetic material to enter the cells. Within a short time, the virus takes over and forces the cells to produce thousands of new virus particles.
In response to this viral invasion, the body marshals its defenses: The nose and throat release chemicals that spark the immune system; injured cells produce chemicals called prostaglandins, which trigger inflammation and attract infection-fighting white blood cells; tiny blood vessels stretch, opening up space to allow blood fluid (plasma) and specialized white cells to enter the infected area; the body temperature rises, enhancing the immune response; and histamine is released, increasing the production of nasal mucus in an effort to trap viral particles and remove them from the body.
As the battle against the cold virus rages on, the body counterattacks with its heavy artillery: specialized white blood cells called monocytes and lymphocytes; interferon, often called the "body's own antiviral drug"; and 20 or more proteins that circulate in the blood plasma and coat the viruses and infected cells, making it easier for the white blood cells to identify and destroy them.
The symptoms you experience as a cold are actually the body's natural immune response. In fact, by the time you feel like you're coming down with a cold, you've likely already been infected for a day and a half. Once you are infected, however, you can try to ease some of the aches and pains. In the next section, we will review some home remedies for relieving cold symptoms.
The cold virus can take many routes to its ultimate destination -- your cells. Most people are contagious a day before and two to four days after their symptoms start. Here are the typical ways a cold virus is spread:
One study found that kids tend to get colds from more direct contact, while adults tend to get colds from airborne viruses (moms of young children can expect to get colds both ways). Research has also found that emotional stress, allergies that affect the nasal passages or throat, and menstrual cycles may make you more susceptible to catching a cold. |
- To see all of our home remedies and the conditions they treat, go to our main Home Remedies page.
- The common cold is rarely life threatening, but it can really take the spring out of your step. Get your pep back by reading Herbal Remedies for Colds.
- Learn safe, practical remedies for avoiding the flu at How to Prevent the Flu.
- Home Remedies for Fevers provides tips for alleviating the discomfort of having a temperature.
- For self-help for flu symptoms, read Home Remedies for the Flu.

