Two years ago, my 18 year old sister was diagnosed with Graves Disease, a thyroid issue. She has since gotten it well under control with medications from her doctor. Unfortunately, a couple months ago, she started having new symptoms, and has been ill ever since. She often gets a very high heart rate, she becomes very pale. she has uncontrollable chills, or terrible fatigue, and dizziness. She also feels very faint, like she will pass out, and occasionally has had trouble breathing. Her thyroid specialist told her last week that her Graves Disease was so well under control, they could take her off the medicine within a month. She has seen a neurologist, two cardiologists, and numerous other specialists, and has been to the ER half a dozen times in the last three months, and we have yet to hear a single diagnoses. She remains without any idea of what is causing this, so there are no medicines or other options. She has returned to the hospital tonight, and I'm sure they will simply tell us that they don't know what caused it, like last time. I don't know where else to turn. Thank you for your help.