question: I am 45, female, weight is 110 lbs, height is 50.  Recently I have difficulty breathing when I walk...my arms hurt and my chest hurts.  I have already been to the cardiologist and all tests were done and everything is fine.  If I take Zyrtec I feel a little better...could it be allergies?  or something wrong with my circulation?  Thank you for any advice you can offer...