Uncontrolled high blood sugar increases your risk for developing heart and blood vessel disease. This can lead to heart attacks and strokes, which is the leading cause of death for people with diabetes. Microvascular (small blood vessel) complications from diabetes include damage to eyes (retinopathy), kidneys (nephropathy), and nerves (neuropathy). These complications, if not cared for properly, can lead to loss of eyesight, renal failure, and nerve damage.