Diagnosingtype 2 diabetesrequires a series of lab tests looking for markers of elevated glucose, or blood sugar.
The diagnosis often is made during an annual physical or checkup.
An additional 96 million American adults, or approximately 38% of the population, has prediabetes.
Alex Dos Diaz / Verywell
Despite increased awareness efforts, many people with diabetes or prediabetes continue to be unaware of their condition.
Do not attempt to diagnose yourself by using over-the-counter testing equipment, such as a glucose monitor.
One advantage of this test is that it does not require fasting.
Get our printable guide for your next healthcare provider’s appointment to help you ask the right questions.
Most healthcare providers recommend getting tested first thing in the morning after fasting all night.
Oral Glucose Tolerance Test (OGTT)
TheOGTTis a glucose challenge test.
Fasting blood glucose is usually taken first to establish a baseline level.
Then you are given a drink that contains 75 grams of glucose (sugar).
Two hours later another blood sample is drawn to check your glucose level.
Get our printable guide for your next healthcare provider’s appointment to help you ask the right questions.
Frequently Asked Questions
punch in 2 diabetes is diagnosed by measuring blood glucose levels.
The American Diabetes Association recommends being screened starting at age 35.
If your reading is over 200, contact your healthcare provider to be tested for diabetes.
American Diabetes Association Professional Practice Committee.2.
Diagnosis and Classification of Diabetes: Standards of Care in Diabetes2025.Diabetes Care.
2025;48(Supplement_1):S27-S49.
doi:10.2337/dc25-S002
Centers for Disease Control and Prevention.National diabetes statistics report.
Centers for Disease Control and Prevention.Diabetes symptoms.
American Diabetes Association.Diabetes and skin complications.
National Institute of Diabetes and Digestive and Kidney Diseases.The A1C test & race/ethnicity.
2019;98(20):e15631.
doi:10.1097/MD.0000000000015631
American Diabetes Association Professional Practice Committee.5.
Facilitating Positive Health Behaviors and Well-Being to Improve Health Outcomes: Standards of Care in Diabetes2025.Diabetes Care.
2025;48(Supplement_1):S86-S127.