Criteria for the Diagnosis of Diabetes Mellitus

1. Symptoms of diabetes plus casual plasma glucose concentration >/=200 mg/dl (11.1 mmol/l). Casual is defined as any time of day without regard to time since last meal. The classic symptoms of diabetes include polyuria, polydipsia, and unexplained weight loss.


2. Fasting Plasma Glucose (FPG) >/=126 mg/dl (7.0 mmol/l). Fasting is defined as no caloric intake for at least 8 h.


3. Hemoglobin A1C >/=6.5%. The test should be performed in a laboratory using a method that is National Glycohemoglobin Standardization Program (NGSP) certified and standardized to the Diabetes Control and Complications Trial (DCCT) assay.


4. Two-hour postload glucose >/=200 mg/dl (11.1 mmol/l) during an Oral Glucose Tolerance Test (OGTT). The test should be performed as described by WHO, using a glucose load containing the equivalent of 75 g anhydrous glucose dissolved in water.

In the absence of unequivocal hyperglycemia, these criteria should be confirmed by repeat testing on a different day. The third measure (OGTT) is not recommended for routine clinical use.



  1. American Diabetes Association. Diagnosis and Classification of Diabetes Mellitus. Diabetes Care. 2012 Jan;35(suppl_1):S64-S71. [Medline]

Created: April 16, 2005