Might help. It's an easy blood test and could help distinguish the two diseases. If the thyroid test is positive, treat that first. Good luck.
Test for panic. The medical conditions that need to be ruled out include dysautonomia (dysregulation of the peripheral nervous system), pheochromocytoma a tumor producing Epinephrine above the kidney is another condition, if your a man, low testosterone and high Estradiol levels, dehydration and excessive use of drinks containing potassium can cause panic and lastly excessive caffeine intake (tea, coke, etc).