Kidneys are an integral part of the body, which helps filter all the toxins and wastes from the body. It comprises tiny blood vessels that help the organ function efficiently. However, high blood sugar may cause damage to these blood vessels, which can in turn lead to diabetic kidney disease, also known as diabetic nephropathy. Symptoms include: protein in the urine, increased need to urinate, worsened blood pressure control, swelling in the feet, ankles, hands and eyes, nausea, vomiting, fatigue and more.