Monitoring and keeping track of your blood glucose (sugar) is very important because it’s the main form of keeping your diabetes under control. It can be tracked using several different kinds of tools. Blood glucose should be especially monitored in patients taking insulin, patients who are pregnant, those have difficulty with blood glucose control, patients that have low blood sugar levels with or without warning signs, or patients who have ketones. Ketones are molecules that can be detected in a urine test and are made when there is not enough insulin in the blood. The body then starts to use fat for energy instead of glucose. Ketones are more common in the urine of patients with type 1 diabetes.

Sources:

http://www.diabetes.org