Diabetic ketoacidosis (DKA) is a serious and potentially life-threatening complication of diabetes. While clinical trials and observational studies have traditionally included DKA events as part of their safety analyses, several studies have looked specifically at the levels of blood β-hydroxybutyrate associated with DKA in both type 1 diabetes (T1D) and type 2 diabetes (T2D) populations. However, in the findings from these studies, all of the reported data on ketone levels were obtained in the presence of elevated glucose levels or DKA symptoms, using episodic ketone testing via urine ketone test strips. In this report, we present findings from a real-world analysis that investigated patterns of blood ketone testing in people with diabetes using the FreeStyle Libre Continuous Glucose Monitoring system. We also report preliminary case studies from a study currently underway that utilizes a novel dual glucose-ketone sensor to elucidate the glucose and ketone variations in a daily life in people with T1D or T2D who are treated with insulin or sodium-glucose transporter-2 inhibitors therapy.