SN instructed that the main job of the kidneys is to filter wastes and extra water out of your blood to make urine. Your kidneys also help control blood pressure and make hormones that your body needs to stay healthy.High blood glucose, also called blood sugar, can damage the blood vessels in your kidneys. When the blood vessels are damaged, they don’t work as well. Many people with diabetes also develop high blood pressure, which can also damage your kidneys