Sneezing, scratchy throat, runny nose -- everyone knows the first signs of a cold, probably the most common illness known. Although the common cold is usually mild, with symptoms lasting 1 to 2 weeks, it is a leading cause of doctor visits and missed days from school and work. According to the Centers for Disease Control and Prevention, 22 million school days are lost annually in the United States because of the common cold.
In the course of a year, people in the U.S. suffer 1 billion colds, according to some estimates.
When it comes to healthy habits, can there be too much of a good thing? Absolutely. Eating wholesome foods helps keep you healthy, but overeating will make you fat and prone to illness. Exercise helps keep you fit, but working out too hard or too often can cause injury and fatigue.
Of course, these are only two of the most obvious examples of how healthy habits can backfire. Here are seven more:
1. Cleaning your kitchen. No doubt about it -- a dirty kitchen can raise the risk of contracting...
Children have about 6 to 10 colds a year. One important reason why colds are so common in children is because they are often in close contact with each other in daycare centers and schools. In families with children in school, the number of colds per child can be as high as 12 a year. Adults average about 2 to 4 colds a year, although the range varies widely. Women, especially those aged 20 to 30 years, have more colds than men, possibly because of their closer contact with children. On average, people older than age 60 have fewer than one cold a year.
In the U.S., most colds occur during the fall and winter. Beginning in late August or early September, the rate of colds increases slowly for a few weeks and remains high until March or April, when it declines. The seasonal variation may relate to the opening of schools and to cold weather, which prompt people to spend more time indoors and increase the chances that viruses will spread to you from someone else.
Seasonal changes in relative humidity also may affect the prevalence of colds. The most common cold-causing viruses survive better when humidity is low—the colder months of the year. Cold weather also may make the inside lining of your nose drier and more vulnerable to viral infection.