Your body uses blood glucose, sometimes known as sugar, as its primary energy source. It originates in the food you eat and is transported to every cell in the body via the blood to be used for a variety of purposes. Blood sugar levels rising indicate the presence of diabetes, either Type 1 or Type 2, or prediabetes. Diabetes is defined as a value of 126 mg/dL while fasting or higher than 200 mg/dL following two hours of eating or consuming a glucose drink. Your readings are regarded as prediabetic if they fall within the range of 100 to 125 mg/dL. If you have prediabetes, are over 35 years old, have a body mass index greater than 25, or are a pregnant woman with diabetes, you should test your blood glucose levels on a regular basis. This test can be used to track your progress toward your overall treatment goals, identify high or low blood sugar levels, monitor the impact of diabetes medications, learn how diet and exercise affect blood sugar levels, and comprehend the effects of other factors like illness or stress on blood sugar levels. A fasting sample is required for this test. The patient is then given 75 g of glucose drink, and samples are collected every 30 minutes, an hour, two hours, 2.5 hours, three hours, four hours, and five hours. Before all the samples are collected, you are not allowed to eat or drink. Patients who respond slowly to a glucose load are advised to get this test.