Most people who have had a blood glucose level over 200mg are considered to be into uncontrolled diabetis. When blood glucose level gets more, generally, the cause is uncontrolled diabetes. The effects of having a consistent high blood glucose level over 500mg can be devastating on the body which can cause complications such as heart disease and stroke, blindness, hypertension, diabetic neuropathy, nerve damage, depression, complications with feet, kidney disease and limb amputation. Meet your doctor and get dose adjustm,ents. Keep control over what yu eat. It too plays a big role in raising your sugar levels.