I feel for you. Try and find a doctor that will do a tilt table test. My son has been sick since December 2010. He was put through a tilt table in October 2011 and was diagnosised with POTS. However, our cardiologist wanted it to be confirmed and referred us to Mayo in Rochester. My son saw those doctors in December 2011 and he does have POTS. Since our Mayo visit, some other unusual symptoms have appeared and we probably will be making another trip to a different clinic soon. The best advice I can give is go to a clinic that is doing research on your daughters symptoms, so you can understand any underlying conditions that are affecting the POTS. Our son has not been able to attend school since January 2011. I hope you find the answers you need. I am a former special education teacher and had to quit my job because my son's medical condition is unpredictable. POTS comes with the good, the bad, and ugle days. My family is adjusting and we take one day at a time. If you would like to read about our family's journey, I started a blog called survivingpots.com. Many of my friends, chruch members and former students read the blog so they can keep up with my son's condition. There is no foul language in my blog. I believe that my God has a plan for my son and family.