Is a blood pressure of 150/85 normal in a 57 year old man?

It is borderline: Ideal blood pressure would be under 120/80, and borderline would be 120-140/ 80-90. BP is v sensitive to activity and stress and yours should be followed and repeated after sitting quietly for 10 minutes. If you are suffering from back pain that would make it go up a bit, and the caffeine also. Cutting back salt and caffeine, relaxation, pain control and moderate walking will likely help.