I have creatinine serum of 1.64, bun 15 and bun to creatinine ratio of 9. an ultrasound of the kidneys revealed no stones or blockage. is kidney damage confirmed?

Yes, but: You do have some kidney issues, but the cause is unclear from the info you have given. Have you seen a nephrologist?

Need more info: A 24 hr urine collection to calculate creatinine clearance would be most accurate in this situation. A level of 1.6 implies a possible decrease in kidney function, but creatinine alone is insufficient to determine absolute renal function. Age, sex, race and muscle mass can have an effect on creatinine. A nephrologist can monitor this and give guidance as to how to preserve remaining function.

I doubt it: Serum creatinine in the absence of kidney failure reflects muscularity and 1.6 has historically been within normal limts. Especially when i'm lifting & fit my creatinine runs at least 1.5. Many pathologists & nephrologists are unhappy with the fad of diagnosing kidney trouble in people us; the "african" adjustment is even added because blacks are supposedly more muscular. BUN 15? Bet you're good.

Elevated creatinine: Your creatinine (c) is most likely elevated and you do not have a cause. It could be elevated from a disease of the kidney you are not aware of. Other causes of elevated c levels are drugs like Motrin (m) and the c falls once m-like drugs are stopped see a nephrologist to have your urine collected for 24 hours and have some blood drawn so the cause of your high c can be found.