What Causes Elevated Calcium Levels Prior To Surgery For Partial Thyroid Removal?

Hi I have elevated calcium levels as I am awaiting surgery to remove the right lobe of my thyroid and also a adenoma in the right upper parathyroid. I am feeling very sick, tired and weak and wondering how dangerous it is to my health if my calcium levels go above 3.0. I was treated in the hospital once already for calcium level of 3.06 with an Iv wash.