Kidney s damaged 50%, how do v recover d other 50%?

Usually permanent: You should be under a nephrologist. Kidney damage is almost invariably permanent. Important thing is to preserve what function remains. Hopefully damage is not progressive. Try to avoid any uti's. Find out if you might benefit from any corrective surgery. Limit protein & salt intake. 50% kidney function is more than sufficient to avoid need for dialysis or a kidney transplant. Good luck.