Global Major Diabetes Diagnostic Criteria Reference
Important Notice: The content on this page is compiled from publicly available authoritative sources and is for learning and reference purposes only. It cannot replace professional medical advice. If you suspect you have diabetes risk, please consult a doctor and seek diagnosis through regular medical institutions.
Diabetes diagnosis is based on a series of standardized blood glucose tests. Below, we summarize the core diagnostic criteria released by the World Health Organization (WHO), China’s National Health Commission (NHC), and the American Diabetes Association (ADA) and other international authoritative organizations. These criteria are widely adopted globally.
Diagnostic Test Items
Diagnosis usually relies on one or more of the following test results, and typically requires repeat testing for confirmation (except for those with acute hyperglycemia symptoms).
- Glycated Hemoglobin (HbA1c): Reflects average blood glucose levels over the past 2-3 months.
- Fasting Plasma Glucose (FPG): Blood glucose level after at least 8 hours of fasting.
- Oral Glucose Tolerance Test (OGTT) 2-hour Blood Glucose: Blood glucose level 2 hours after drinking 75g of anhydrous glucose.
- Random Blood Glucose: Blood glucose level at any time of day, combined with typical hyperglycemia symptoms (polydipsia, polyuria, polyphagia, unexplained weight loss).
Major Organizations Diagnostic Criteria Comparison Table
The following table shows the main numerical thresholds for diagnosing Diabetes Mellitus and Prediabetes:
| Test Item | Normal | Prediabetes | Diabetes |
|---|---|---|---|
| HbA1c | < 5.7% |
5.7% - 6.4% (ADA) 6.0% - 6.4% (WHO) |
≥ 6.5% |
| Fasting Glucose (FPG) | < 5.6 mmol/L (< 100 mg/dL) |
5.6 - 6.9 mmol/L (100 - 125 mg/dL) |
≥ 7.0 mmol/L (≥ 126 mg/dL) |
| OGTT 2-hour Glucose | < 7.8 mmol/L (< 140 mg/dL) |
7.8 - 11.0 mmol/L (140 - 199 mg/dL) |
≥ 11.1 mmol/L (≥ 200 mg/dL) |
Key Explanations and Interpretations
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China Standards: The standards issued by China’s National Health Commission in the “Chinese Type 2 Diabetes Prevention and Treatment Guidelines” are basically consistent with those of WHO and ADA, mainly using Fasting Plasma Glucose (FPG) and OGTT 2-hour Blood Glucose as diagnostic basis. In recent years, HbA1c has gradually been included in China’s diagnostic system, with a standard value of ≥6.5%.
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Diagnostic Confirmation: In the absence of clear hyperglycemia symptoms, any abnormal test result requires confirmation by repeat testing on another day. For example, if the first fasting glucose is 7.2 mmol/L, the doctor would recommend a follow-up fasting glucose test or an OGTT test.
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Use of Random Blood Glucose: If a patient has obvious hyperglycemia symptoms (polydipsia, polyuria, polyphagia, unexplained weight loss), and the random blood glucose value is ≥ 11.1 mmol/L (≥ 200 mg/dL), diabetes can be diagnosed without waiting for retesting.
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Prediabetes: This stage is an important warning signal, indicating that the patient’s blood sugar regulation ability is already impaired, and it is a high-risk period for developing full diabetes. Through active lifestyle intervention, prediabetes can be reversed or its progression delayed.
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Ethnic Differences: Although the numerical diagnostic criteria are unified, there may be differences in risk among different ethnic groups at the same blood glucose level. For example, some studies show that Asians may develop insulin resistance at relatively lower body mass indexes (BMI). Therefore, regardless of ethnicity, regular check-ups and attention to one’s own risk factors are very important.