500mg/dl is a very high blood glucose that needs attention from a health professional. the american diabetes association recommends the following blood glucose levels for people with diabetes: 70 to 130 mg/dl before meals and less than 180 mg/dl after meals. when blood sugar levels remain too high ketoacidosis can result (click on the link for more info) but that is more likely to occur in someone with type 1 diabetes. over time having high blood sugars puts people at risk for various complications. it's important you work with your doctor to lower your blood glucose level as is working with your dietitian/diabetes educator to make changes to your meal plan and/or medication. don't delay getting help! there is quite a learning curve when diabetes is first diagnosied but once you get it it will become easier. for more on blood sugar control see this webmd article
what happens when glucose levels go over 250? my husband's is reading 500. he was recently diagnosed with diabetes.