You asked me that in another post so I've just copied the answer here:
It was a burning sensation just below the adams apple, I actually thought it was indigestion.
I had no other symptoms - the 'pain' would come with exercise, walking fast, climbing stairs etc;
It would also come if I was stressed about something or got emotional such as being annoyed at other drivers.
At first it only came maybe once every couple of months, then I started getting it a few times a week - that's when I went to have it checked out.
It only lasted a minute or so at the most and would always go away once I sat down and relaxed.