Which test is primarily used to diagnose hypoglycemia?

The 5-hour oral glucose tolerance test (GTT) is primarily used to diagnose hypoglycemia by assessing how the body processes glucose over an extended period. During this test, a patient consumes a glucose solution, and blood glucose levels are measured at intervals, typically for up to five hours. This allows for a comprehensive evaluation of the body's insulin response and glucose metabolism.

Hypoglycemia occurs when blood glucose levels drop below normal, and the GTT can help illustrate the pattern of glucose response over time, making it possible to identify anomalies in glucose handling that could lead to hypoglycemic episodes.

While the other tests mentioned can provide valuable information about glucose metabolism and insulin response, they have different primary uses. For example, the glucose tolerance test primarily investigates the body's ability to process glucose and is not solely focused on diagnosing hypoglycemia. The insulin level test measures the amount of insulin in the blood, which is useful for understanding insulin production but does not specifically diagnose hypoglycemia. The fasting blood sugar test assesses baseline glucose levels after fasting, which can indicate hyperglycemia or normal glucose levels but may not be sufficient for diagnosing hypoglycemic events directly, especially without post-glucose challenge data. Thus, the 5-hour oral GTT stands