Agree with Enzy. If imaging is not finding the issue, make sure comprehensive testing is being done.
Something may have caused low blood pressure and hypoglycemia, such as adrenal fatigue. Did he get blood tests done to check this, plus electrolytes?
Has he sustained a head injury anytime in the last six months?
If he continues to have trouble, I hope he can have more tests run to find the cause. He should drink a sports water beverage, to keep replenishing his electrolytes. Avoid Gatorade and food coloring.