This document summarizes key aspects of glucose homeostasis and diabetes. It discusses how glucose levels are tightly regulated in the body and maintained within a narrow range. It describes the roles of organs like the liver, muscles and adipose tissue in glucose metabolism and storage. It also outlines the diagnostic criteria and tests used to diagnose diabetes, including fasting plasma glucose, oral glucose tolerance tests and HbA1c levels. The document compares types 1 and 2 diabetes and discusses gestational diabetes as well.