Screening for Type 2 Diabetes

Screening is a way to check for type 2 diabetes in people who do not have symptoms of the disease, but who may likely develop diabetes in the future. Diabetes can lead to serious health problems, but finding diabetes early allows for early treatment.


  • Family history of diabetes.

  • Diseases of the pancreas.

  • Obesity or being overweight.

  • Certain racial or ethnic groups:

  • American Indian.

  • Pacific Islander.

  • Hispanic.

  • Asian.

  • African American.

  • High blood pressure (hypertension).

  • History of diabetes while pregnant (gestational diabetes).

  • Delivering a baby that weighed over 9 pounds.

  • Being inactive.

  • High cholesterol or triglycerides.

  • Age, especially over 45 years of age.



  • Adults who have no risk factors and no symptoms should be screened starting at age 45. If the screening tests are normal, they should be repeated every 3 years.

  • Adults who do not have symptoms, but are overweight, should be screened before age 45.

  • Adults who do not have symptoms, but have 1 or more risk factors, should be screened.

  • Adults who have an A1c (3 month average of blood glucose) greater than 5.7% or who had an impaired glucose tolerance (IGT) or impaired fasting glucose (IFG) on a previous test should be screened.

  • Pregnant women with or without risk factors should be screened.

  • Women who gave birth and had gestational diabetes should be screened. This testing should be done 6 to 12 weeks after the child is born. 

Children or Adolescents

  • Children and adolescents should be screened for type 2 diabetes if they are overweight and have 2 of the following risk factors:

  • Having a family history of type 2 diabetes.

  • Being a member of a high risk race or ethnic group.

  • Having signs of insulin resistance or conditions associated with insulin resistance.

  • Having a mother who had gestational diabetes while pregnant with him or her.

  • Screening should start at age 10 or at the onset of puberty, whichever comes first. This should be repeated every 2 years.


In a screening, your caregiver may:

  • Ask questions about your overall health. This will include questions about the health of close family members, too.

  • Ask about any diabetes-like symptoms you may have.

  • Perform a physical exam.

  • Order some tests that may include:

  • A fasting plasma glucose test. This measures the level of glucose in your blood. It is done after you have had nothing to eat but water (fasted) for 8 hours.

  • A random blood glucose test. This test is done without the need to fast.

  • An oral glucose tolerance test. This is a blood test done in 2 parts. First, a blood sample is taken after you have fasted. Then, another sample is taken after you drink a liquid that contains a lot of sugar.

  • An A1c test. This test shows how much glucose has been in your blood over the past 2 to 3 months.