The purpose of screening is early diagnosis and treatment. Screening tests are usually administered to people without current symptoms, but who may be at high risk for certain diseases or conditions.

Screening Guidelines

It is estimated that 16 million Americans have prediabetes. This condition is characterized by high blood glucose levels that are not high enough to be diagnosed as diabetes. But, the condition often progresses to type 2 diabetes.

In order to detect prediabetes and take steps to prevent its progression to type 2 diabetes, the American Diabetes Association (ADA) recommends the following guidelines:

  • Screening in adults of any age who are overweight or obese with one or more of these risk factors:
    • First-degree relative with diabetes
    • Low HDL (good) cholesterol level and high triglycerides levels
    • High blood pressure
    • History of diabetes during pregnancy (gestational diabetes) or having a baby weighing over nine pounds (4.1 kg)
    • Having polycystic ovary syndrome or other conditions associated with insulin resistance
    • Being inactive
    • History of cardiovascular disease
    • Belonging to an at-risk ethnic group (African American, Hispanic, Native American, Hispanic American, Asian American, or Pacific Islander)
    • Previous blood test results that show hemoglobin A1c (HbA1c) levels at 5.7% or higher, impaired glucose tolerance, and impaired fasting glucose
  • Screening in adults aged 45 and older with or without risk factors
  • Screening in overweight children aged 10 years and older who have two of the following risk factors:
    • High body mass index (BMI) based on child's weight and height
    • Family history of diabetes
    • Signs of insulin resistance or having a condition associated with insulin resistance
    • At-risk ethnic background

If the results are normal for both adults and children, the ADA recommends screening again in three years.

Screening Tests

As part of your routine physical exam, your doctor may draw some blood to check your liver, kidney, and endocrine functions, including blood glucose. This blood is taken any time of day, without regard to when you have last eaten. A measure of 200 milligrams per deciliter (mg/dl) [11.1 mmol/L] may indicate diabetes. In this case, your doctor will do further testing to determine if you have diabetes.

Blood glucose testing is often done at health fairs, as well. Here, you will need to give only a few drops of blood from your fingertip, and you will have results within a few minutes. If the results indicate that your blood glucose level is high, you should see your doctor for further testing. Keep in mind, though, that the results from a health fair screening are not as accurate as the tests that your doctor does.