Amylase serum is normal 96 (ref <101 units/l) amylase urine is 27 (ref 0 - 15 units/hr). why would urine's elevated and not serum? i have no symptoms, mrcp, ct scan all normal.

Lab error?: If everything else is normal, could be lab error. Or could be the urine lags the serum. The serum might have been high and now the urine is high. The serum is now back to normal and the urine will follow.

CLEARANCE: There are multiple types of amylase enzyme in blood stream and you are clearing them thru the kidney at a faster rate than "normal" also there are normal people who fall outside the normal parameters--simply the way normals are determined with all the neg studies/no symptoms i would not worry and would not pursue further.