Diabetes Lab Tests 101

Diabetes Lab Tests 101

If your healthcare provider thinks you may have type II diabetes, what tests need to be run to make a diagnosis? If you have type II diabetes, what tests can help you manage your glucose levels?

Tests that Diagnose Type 2 Diabetes

Your healthcare provider can use 1 or more of the following blood tests to diagnose you with type 2 diabetes. These tests measure the level of glucose in your blood.

  • An A1C test measures your average glucose level over the last 2 to 3 months. A result of 5 percent or higher means diabetes.
  • A fasting glucose test measures your glucose level when you had nothing to eat or drink, except water, for at least 8 hours. A result of 126 mg/dL (milligrams per deciliter) or higher means diabetes.
  • A random glucose test measures your glucose level at any time of day when you have been eating and not fasting. A result of 200 mg/dL or higher with symptoms (tiredness, blurred vison, cuts or sores that do not heal, dry, itchy skin, increased urination, pain or numbness in feet or hands) means diabetes.
  • An oral glucose tolerance test measures your glucose level when you have had nothing to eat or drink, except water, for at least 8 hours. Then the test measures your glucose level again after 2 hours after you drink a sweetened beverage. A result of 200 mg/dL or higher means diabetes

If your tests results were high, your provider may have you take a test again on another day. If both tests are positive for type II diabetes then your diagnosis is confirmed.

Tests that monitor your glucose level

Two blood tests help you manage your diabetes. Your provider will order an A1C laboratory test. The other test you do yourself at certain times each day. This test involves checking the glucose level in your blood from a finger poke.

Together, these tests let you know how well your treatment plan is working. They also help you and your care team decide whether changes to your plan are needed.

  • The A1C is a laboratory test that shows your average glucose level over the last 2 to 3 months. Standard recommendations are to have an A1C test every 3 to 6 months. A normal A1C is 4 to 5.4 percent. The target for most people with diabetes is less than 7 per cent. Your target may be slightly different.
  • Using a glucose meter is the 2nd test you will use to check your glucose levels. This is another way to see if your diabetes is being managed. This check takes only a few seconds with a glucose meter. The result of this check tells you what your glucose level is at that moment. Target levels for times to check are shown in the table below:

 

Target Glucose Levels
Time to Check Diabetes Target

(mg/dL)

Before a meal 80-130
1 to 2 hours after the start of a meal Less than 180