I understand several tests have been done. However I am again enumerating all the
causes which should be looked into. You need to get your daughter examined to rule out a few things such as low blood pressure, postural hypotension, cervical spinal nerve compression, hypoglycemia, severe anemia, an underactive thyroid (called hypothyroidism), overactive thyroid (called hyperthyroidism), adrenal insufficiency (called Addison's disease), GERD, and internal ear infections.