The symptoms of diabetes include fatigue, nausea, a need to urinate frequently, excessive thirst, weight loss, blurred vision, frequent infections, and sores that do not heal. However, some people with diabetes do not have any symptoms. Over time, the high blood glucose levels caused by diabetes can lead to complications in the eyes, blood vessels, nerves, kidneys, feet, teeth, skin, and, especially, the heart. Such complications can be prevented or delayed by keeping blood glucose, blood pressure, cholesterol, and triglycerides in a normal or close-to-normal range.