Anxiety, defined by Google is "worry, stress and fear."  These emotions are all "futuristic" meaning we feel them by having thoughts about the future.  They are created by our thoughts and are unnecessary, as we have no control over what might be... the future!  
Feeling fearful, anxious and stressed is actually feeling, for no reason, the feelings you would feel, IF what you are worrying about, actually happened."  Why not wait until it happens, IF it actually happens.  When we control our thoughts, we control our own fear, stress and anxiety.