Can low potassium in the blood or body injure the kidneys? why? what's the solution to this?

This is complicated: Very low potassium can injury any cell in the body (less than 2-ish) low potassium is happening for a reason - for most people it is a problem that the kidney is excreting the potassium out of the body - many times it is caused by a medicine that makes your kidneys excrete the potassium. There are potassium sparing diuretics that help you retain potassium but needs to be prescribed and monitored.