Anxiety is a normal reaction to a threatening situation and results from an increase in the amount of adrenaline from the sympathetic nervous system. This increased adrenaline speeds the heart and respiration rate, raises blood pressure, and diverts blood flow to the muscles. These physical reactions are appropriate for escaping from danger but when they cause anxiety in many situations throughout the day, they may be detrimental to a normal lifestyle. An anxiety disorder is a disorder where feelings of fear, apprehension, or anxiety are dis ....