There are several tests doctors can use to make a diabetes diagnosis and monitor your condition. Below are the most common tests, along with why you need them, and what they can tell you about your condition.

  • Fasting plasma glucose test: This blood test measures the glucose in your blood after at least eight hours of fasting. You should have only sips of water before the test. It's usually done in the morning.
  • A1C test: This blood test measures your average blood glucose over the past three months. You do not need to fast for this test. Tell your doctor if you've been diagnosed with anemia; a low red blood cell count can affect the results of this test.
  • Random plasma glucose test: This blood test can measure your blood glucose level at any time. You might have this test if you have symptoms of diabetes and your doctor wants to know your blood glucose level without waiting for fasting.
  • Glucose challenge test: This blood test measures your blood glucose level one hour after your swallow a sugary drink. You do not need to fast first. This test is often used to check for gestational diabetes.
  • Oral glucose tolerance test: This blood test measures your blood glucose level after fasting and having a sugary drink. Your blood is taken four times: after fasting and one, two and three hours after the sugary drinks.
  • Autoantibodies test: This blood test checks for proteins in your blood called antibodies. They may be present if you have type 1 diabetes. This test is often used to diagnose type 1 diabetes.