Diabetes Screening: Early Detection Saves Lives

Guide to diabetes screening tests, who needs screening, and how to interpret results for early disease detection.

10 min readLast updated: 2026-02-17

Quick Facts

Prevalence
Over 37 million Americans have diabetes
Undiagnosed
1 in 5 people with diabetes don't know they have it
Prediabetes
96 million Americans have prediabetes

Overview: Why Diabetes Screening Matters

Type 2 diabetes often develops silently without noticeable symptoms. Early detection through screening allows intervention before complications develop, potentially preventing or delaying disease progression .

Screening is particularly important because prediabetes—an intermediate stage—can be reversed with lifestyle changes. Identifying prediabetes and diabetes early provides the best opportunity for successful management.

Key Information
Screening involves simple blood tests: fasting glucose, hemoglobin A1c (HbA1c), or oral glucose tolerance tests (OGTT). Results categorize you as normal, prediabetic, or diabetic.

Who Needs Screening?

All adults age 45 and older should be screened. Younger adults with risk factors—including overweight/obesity, sedentary lifestyle, family history, or certain ethnicities—should be screened earlier.

Screening Tests

The fasting blood glucose test measures glucose after 8+ hours without food. The HbA1c test shows average blood sugar over 3 months. The oral glucose tolerance test reveals how your body handles glucose after consuming sugar.

Warning
Don't ignore prediabetes diagnosis. Lifestyle changes can prevent or delay type 2 diabetes development by up to 58% in adults over 60.
Clinical Note
The American Diabetes Association recommends screening every 3 years for normal results, more frequently if prediabetes is identified . Structured lifestyle programs focusing on weight loss, diet, and exercise show remarkable effectiveness.

Understanding Results

Normal fasting glucose is below 100 mg/dL. Prediabetes ranges from 100-125 mg/dL. Diabetes is diagnosed at 126 mg/dL or higher on two separate tests or single fasting test plus symptoms.

Sources

  1. [1]American Diabetes Association. "Standards of Medical Care in Diabetes 2017." Diabetes Care, 2017.
  2. [2]Seneviratne R et al.. "Screening and diagnosis of type 2 diabetes in adults." Prim Care, 2019.

Medically reviewed by

Medical Review Team, Endocrinology

Last updated: 2026-02-17Sources: 2

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