What Causes Dizziness And Shortness Of Breath After Esophagram?

I was admitted to the hospital and had a 7.1 hgb...after multiple blood draws they did an esophagram and kept drawing. The said they woul not transfuse unless it went to 7.0.......they sent me home with meds at 7.0....at the hospital I had been calm and ok. now at home i m dizzy and short of breath. please assess and advise.