Anxiety refers to feelings of worry, nervousness, or a sense of apprehension, typically about an upcoming event where the outcome is uncertain, or where the person feels he or she might not be up to the task. Anxiety is commonly experienced in high pressure situations, for example, when you are about to make a speech or sit an exam.
Anxious feelings are usually accompanied by physical sensations such as a churning stomach, light headedness, and a racing heart. These are all normal reactions to these types of situations.