Finding a small contracted kidney commonly occurs as you have described. It is incidentally discovered during a scan for other reasons. It is impossible to tell why the kidney is small and contracted. The most likely reason is because you were born with a small left kidney. Once a kidney is small and contracted, it cannot be made to grow and return to a normal size. The goal of care at this point should be to protect your remaining normal kidney and prevent any damage to this kidney. I recommend that you continue to monitor your kidney function with annual testing of your blood and urine. There is no treatment necessary for the small and contracted kidney.
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