An oral glucose tolerance test (OGTT) is a medical procedure used to assess how well the body processes sugar. During the test, a person fasts overnight and then drinks a sugary solution. Blood samples are taken at intervals to measure how quickly glucose is cleared from the bloodstream. The OGTT helps diagnose conditions like prediabetes and type 2 diabetes. It provides valuable information about insulin sensitivity and how the body responds to sugar intake, guiding healthcare providers in managing and preventing diabetes-related complications.