Prediabetes: Which Blood Tests Are Commonly Used?
The main blood tests for prediabetes are A1C, fasting plasma glucose, and the 2-hour oral glucose tolerance test. Here is how they differ and what results may mean.
Diabetes and Metabolic Health
C-Peptide Blood Test: What It Measures, Preparation, and Results
A C-peptide blood test estimates how much insulin your pancreas is making. Learn when it is ordered, how to prepare, what high and low results can mean, and how direct-to-consumer ordering options compare.
Insulin Blood Test: What It Measures, Preparation, and Results
A fasting insulin blood test measures the amount of insulin in your blood after an overnight fast. Learn why it is ordered, how to prepare, what results may mean, and how to compare self-pay testing options without overpaying.
Fasting Glucose Blood Test: What It Measures, Preparation, and Results
A fasting glucose blood test measures blood sugar after an overnight fast. Learn what the test is used for, how to prepare, how to read common result ranges, and what may happen next.