Shortness of Breath

I am a 36 year old female who has been experiencing shortness of breath.  I feel as though I can never get a full breath of air.  I am a smoker (keep trying to quit).  I have had many test done over the last 2 years.  Have been told after several blood tests for everything use could imagine, ekgs, heart scans and chest x-rays that there is no problem.  I suffer from anxiety and had several panic attacks.  I am no longer having panic attacks , but could anxiety be causing the shortness of breath and if so how do I make it go away.  It is starting to affect me more and more each day.  I get scared and the shortness of breath seems to become worse.  I know that I spend alot of time thinking about my breathing - could this be part of the problem.  I also noticed that when I am busy (playing basketball with my kids or spending time with the family) I really dont notice the shortness of breath as much.   Please help me.

[National Jewish]

It is certainly possible for anxiety to cause shortness of breath.  Spending a lot of time thinking about your breathing will make you more aware of the problem.  The opposite is also true.  Spending little time thinking about your breathing will make you less aware of the problem.  Your statement that you don