Hey all, I gave a pint of blood yesterday for surgery I am having next week. While giving it I started feeling weird, like a hollowness in my chest and they had to tilt the chair up. In the "recovery" area, they again had to assist me and lay me down because I felt weak, and that "hollow" feeling. ALl last night I was so drained and tired, and today I got up and i still feel unwell. What gives?? They said my iron was 11.8 (normal is 12) and said one pint would not hurt me.