insurance coverage.

I am 20, soon to be 21. I have been overweight all of my life. Throughout high school, I was in softball, winter track, band and marching band, i worked, was in honors classes...the list goes on and on. oh, i forgot to say..i have been riding horses and rodeoing all my life. So to say that I was active is an understatement. I am now in college for my RN and work at a local hospital. Again, I am considered "extremely obese" with the BMI calculator. I have high blood pressure which i am trying to manage with diet and exercise (not working) and i have a family history of it and heart disease. I also have problems with my lungs (lost the top lobe of my right lung to pneumonia). I was wondering how hard it is for High mark blue shield to approve you for coverage for surgery. thanks for your help!