Kidney disease is a complication that consists of high blood sugar. When you get Kidney disease high amount of glucose in the blood make the kidneys work way harder than they should be. Diabetics should worry about this complication because the extra work breaks down the body's filters and eventually proteins start to leak out of the blood and into urine. I diabetic would not be getting there main source of energy if they had kidney disease.
Stress is also a disease that consists of high blood sugar. A diabetic should worry about having stress because once a diabetic has stress it can cause and increase on blood glucose, and many other symptoms. If you have diabetes it completely changes the life of a person affected.
Lastly, Neuropathy is a complication in the body that deals with high blood sugar. A diabetic should worry about it because first, you will start to get nerve damage throughout your body, which then causes a decrease to blood flow to nerves, which then causes no blood sugar to get where its needed.