Hi, I understand your concern. 1. You say to have run various tests, can you please send the reports to me so I can evaluate the changes myself? 2. If nothing is found in your kidney or thyroid or other organs, then your high blood pressure (HBP) is due to aging or narrowing of blood vessels. Sometimes, no real cause is known and we name it just essential hypertension). Heredity can play a role too together with your diet and lifestyle regimen. I highly recommend to: - continue regular follow ups with your cardiologist - limit salt intake - eat healthy - be physically active according to your general health status. Hope this helps.