But when people talk about anxiety, they commonly mean something much more terrible than merely a bit of nervous reaction to some unexpected event. Full-blown disorders including panic attacks, post-traumatic stress disorder, and even Obsessive-compulsive disorder are considered forms of anxiety, and whole fields of drug are dedicated to their study.

Some folks experience these symptoms so severely that they're somewhat socially crippled, unable to hold down a job, meet new people, or function outside their home at all.

According to the Federal Institute of Health (NIH), "approx. 40 million American adults ages 18 and older, or about 18.1 percent of people in this age group in a given year, have an anxiety disorder." They also bring out that it's not uncommon for people to suffer from more than one type of anxiety disorder - for instance, somebody experiencing post-traumatic stress disorder may also feel frequent panic attacks. Obsessional compulsive disorder can also be tied to depression, and so on.

18 percent of people is almost one in five, so the next time you think that you're the only one that feels the way you do or are the only one fighting these symptoms, walk through the mall or think of a group of folks you know, such as at work or your place of worship. Chances are that for every five or six people there, commonly one of them has an anxiety disorder of one type or another.