People with anxiety disorders aren't the only people who experience anxiety; in fact, everyone feels it everyday, they just don't know it. Anxiety is what you feel before a big game or an important test. It's the source of excitement before you go on a ski trip at your favorite resort. It's the butterflies in your stomach on a first date. It's what can prepare you for a big event; it's the rush you feel. Depending on how you interpret this feeling, however, it can be your best friend or worst enemy.
People with anxiety disorders get this rush, but deal with it differently. Their mind and body turn this normally helpful emotion into a feeling of helplessness, and don't allow themselves to get motivated. Before big games and important tests, rather than getting inspired to prepare for the event, people with anxiety disorders get the feeling that there's no point in getting ready. They end up concentrating on something much less important because it feels much more comfortable. The rush that usually helps someone deal with a situation becomes the situation they're dealing with. They don't want to feel uneasy so they try and keep their mind off it. The most important thing to a person with this disorder is to get rid of the 'nervousness'; the problem is, the easiest way to do so is to avoid the situation that's causing it.
The mind will make subconscious decisions that postpone or even stop people from dealing with the situation. In the moments before a big event, people easily get distracted and find them selves tempted to engage in another activity. Although they might think it's a good idea to go through with their urges, it's really just a distraction to remove them from the situation in order to lower the anxiety.