I have been to see a doctor because i have been feeling palpitations and rapid heartbeat, as well as being tired. I am being checked for anemia and thyroid disease. I had anemia a couple of years ago. However, i had a blood test 4 or 5 months ago and I was fine. Is it possible to develop anemia or thyroid disorder in only a few months? I anyone know, i would be grateful while awaiting my results!