Active_comparator: Standard of Care

Severe hyperglycemia will be managed by primary care professionals (Hospitalist Service) with intravenous or subcutaneous insulin therapy. Subjects will be invited to participate in the study after the resolution of severe hyperglycemia (BG \< 400 mg/dl). Glucose monitoring by POC testing will be performed before meals and at bedtime. Results will be uploaded to the electronic medical record (EMR) system. The research team, together with the Primary care (PCP) team, will adjust daily insulin orders based on POC readings (standard of care). In addition, subjects will wear a 'blinded' CGM (no results will be visualized by patients, nursing staff, medicine, or research teams) during hospitalization for up to 10 days.

Experimental: Dexcom CGM

Severe hyperglycemia will be managed by primary care professionals (Hospitalist Service) intravenously with subcutaneous insulin therapy. Subjects will be invited to participate in the study after the resolution of severe hyperglycemia (BG \< 400 mg/dl). Subjects will wear a real-time Dexcom G7 CGM for up to 10 days. Insulin therapy will be titrated based on daily CGM reports, including mean glucose, glycemic excursions, hypoglycemia, and severe hyperglycemia \> 180 and \>250 mg/dl values. Participants will wear a Dexcom rtCGM for up to 10 days during hospitalization.