Key Points About Diabetes Testing
- Blood tests are the main way to diagnose diabetes and prediabetes.
- Early testing is important—even if you don’t have symptoms.
- The most common tests include the A1C test, fasting blood sugar, and glucose tolerance test.
- Adults age 45 and older or anyone with risk factors should talk to their doctor about testing.
- Getting tested helps you take control early and prevent serious complications.
What to Expect
Overview: Diagnosing Diabetes
Diagnosing type 1 diabetes, type 2 diabetes, gestational diabetes, or prediabetes begins with blood tests to check how your body handles glucose (blood sugar). In some cases, especially for type 1 diabetes, a urine test may also be used. To confirm a diagnosis, you may need more than one test.
Who Should Get Tested for Diabetes?
Diabetes symptoms can develop slowly, making it hard to notice early signs. That’s why testing is important—even if you feel fine.
You should talk to your Riverside primary care provider about getting tested if:
- You are age 45 or older
- You have one or more risk factors for diabetes, such as:
- Being overweight
- A family history of diabetes
- High blood pressure or cholesterol
- A history of gestational diabetes
Screening for gestational diabetes is usually ordered around the week mark. Talk to your OB/GYN about any concerns.
What to Expect During Diabetes Testing
Depending on your health history and symptoms, your doctor may choose one or more of the following blood tests:
- A1C Test (Glycated Hemoglobin Test)
The A1C test shows your average blood sugar levels over the past 2–3 months.
• A small blood sample is taken and sent to the lab.
• It measures the percentage of sugar attached to your red blood cells.
• Red blood cells live about 120 days, so this test provides a long-term view.
• Higher A1C = higher average blood sugar = increased risk of diabetes.
• This test can help diagnose both type 1 and type 2 diabetes.
• Usually, your doctor will repeat the test to confirm the results.
- Random Blood Sugar Test
• No fasting needed.
• A blood sample is taken at any time of day.
• A level of 200 mg/dL or higher suggests diabetes.
- Fasting Blood Sugar Test
• Requires fasting for at least 8 hours beforehand.
• A normal result is 70–99 mg/dL.
• A reading of 126 mg/dL or higher on two separate tests means you likely have diabetes.
- Glucose Tolerance Test (GTT)
This test is often used to diagnose gestational diabetes and sometimes type 2 diabetes.
Steps include:
• Fast for 8 hours before the test (usually overnight).
• At the doctor’s office, a baseline blood sugar sample is taken.
• You'll drink a sweet glucose drink (orange or cola-flavored).
• Blood sugar is then tested at multiple intervals (usually after 1, 2, and 3 hours).
• You’ll need to stay at the office during the test.
• Afterward, you can return to normal activities.
Your doctor will review the test results with you and decide on next steps based on your numbers.
Next Steps After Testing
• If your results show signs of gestational diabetes, type 1 diabetes, type 2 diabetes or prediabetes, your doctor will recommend a treatment and monitoring plan.
• Make sure to follow up with your doctor if you have any questions about your test results or symptoms.
• Early diagnosis allows for better blood sugar control and lowers your risk of long-term complications.
• If you are diagnosed with diabetes, be sure to review the classes available to help you learn how to manage your condition and stay as healthy as possible.