I dont have kidney disease but I have a question

hello everyone
I had a kidney ultra sound a couple of years ago because something showed up in my blood
the ultra sound came back everything ok
Just recently I had another ultrasound for another reason and the kidneys were checked again as well

I looked at both reports and they both have measurements of the right and left kidneys sizes
and they seem to have shrunk because the measurements are different now
My question is do kidneys shrink and why do they shrink?
i hope this is not a silly question as i would like some feed back if anyone has a answer
thankyou

[vivianwong]

Hi how much have they shrank?

Normal kidneys shouldn't shrink. It usually is a sign of chronic kidney damage over time.

You didn't say what was shown in your blood test? Was it regarding your kidney function?

Is there any blood or protein in your urine?

[Grandmaster]

Whenever i urinate,it do foam.there was a time it stop foaming.but it has started again.and i also feel a little bit of ache in my left kidney.pls wat is happenin 2 me.