Specialists & Providers
Diagnostic Biomarkers
Diagnostic & Clinical Standards
Authoritative clinical thresholds and screening guidelines from major medical bodies.
HbA1c Diagnostic Categories
NIDDK2025
HbA1c (hemoglobin A1c) is a blood test that reflects average blood sugar levels over the past 2-3 months. It is commonly used to classify whether blood sugar levels fall within the normal range, indicate prediabetes, or meet the commonly used diagnostic threshold for diabetes.
Normal
< 5.7%
Prediabetes
5.7 – 6.4%
Diabetes
≥ 6.5%
Blood sugar levels are within the commonly accepted range.
Blood sugar levels are above the commonly accepted normal range but below the diabetes diagnostic threshold. Indicates increased risk for developing type 2 diabetes.
Meets the commonly used diagnostic threshold for diabetes mellitus. Confirmation on a separate day is generally recommended.
FPG Diagnostic Categories
NIDDK2025
The fasting plasma glucose (FPG) test measures blood sugar after at least 8 hours of fasting. It is one of the commonly used tests to classify whether blood sugar levels fall within the normal range, indicate prediabetes, or meet the diagnostic threshold for diabetes.
Normal
< 100mg/dL
Prediabetes (Impaired Fasting Glucose)
100 – 125mg/dL
Diabetes
≥ 126mg/dL
Fasting blood sugar is within the commonly accepted range.
Fasting blood sugar is above the commonly accepted normal range but below the diabetes threshold. Also called impaired fasting glucose (IFG).
Meets the commonly used diagnostic threshold for diabetes mellitus. Confirmation on a separate day is generally recommended.
OGTT Diagnostic Categories
NIDDK2025
The oral glucose tolerance test (OGTT) measures blood sugar 2 hours after drinking a sugary liquid. It is used to classify whether blood sugar levels indicate normal glucose tolerance, prediabetes (impaired glucose tolerance), or diabetes.
Normal
< 140mg/dL
Prediabetes (Impaired Glucose Tolerance)
140 – 199mg/dL
Diabetes
≥ 200mg/dL
Glucose tolerance is within the commonly accepted range.
Glucose tolerance is impaired, indicating increased risk for type 2 diabetes. Also called impaired glucose tolerance (IGT).
Meets the commonly used diagnostic threshold for diabetes mellitus. Confirmation on a separate day is generally recommended.
Random Glucose Diagnostic Threshold
NIDDK2025
A random (non-fasting) blood sugar test of 200 mg/dL or higher, combined with classic symptoms of high blood sugar (such as increased thirst, frequent urination, and unexplained weight loss), meets the commonly used diagnostic threshold for diabetes.
Diabetes (with symptoms)
≥ 200mg/dL
In the presence of classic symptoms of hyperglycemia (polyuria, polydipsia, unexplained weight loss), meets the commonly used diagnostic threshold for diabetes without requiring confirmatory testing.
USPSTF Diabetes Screening
USPSTF2021
The U.S. Preventive Services Task Force recommends that adults aged 35 to 70 who are overweight or obese be screened for prediabetes and type 2 diabetes. Those found to have prediabetes should be offered or referred to effective preventive interventions.
Screen for prediabetes and type 2 diabetes. Offer or refer patients with prediabetes to effective preventive interventions.
Nonpregnant adults aged 35 to 70 years with BMI ≥ 25 kg/m²
Grade B means the USPSTF recommends the service. There is moderate certainty that the net benefit is moderate, or high certainty that the net benefit is moderate.
Treatments & Interventions
Human insulin
substance
Miglitol
substance
Metformin hydrochloride
substance
Tolbutamide sodium
substance
Rosiglitazone maleate
substance
Pioglitazone hydrochloride
substance
Human insulin-containing product
product
Colesevelam hydrochloride
substance
Insulin aspart
substance
Metformin
substance
Tolbutamide
substance
Glibenclamide
substance
Repaglinide
substance
Acarbose
substance
Glimepiride
substance
Troglitazone
substance
Chlorpropamide
substance
Nateglinide
substance
Glipizide
substance
Tolazamide
substance
Clinical Trials
Recent Trials
Family Investigation of Nephropathy and Diabetes (F.I.N.D.)
A Study of Cardiovascular Events iN Diabetes Plus
A Pragmatic Trial Comparing Empagliflozin and Dapagliflozin Through Cluster Randomization Embedded in the Electronic Health Record
EASi-PROTKT™ - A Study to Test Vicadrostat (BI 690517) Taken Together With Empagliflozin in People With Type 2 Diabetes, High Blood Pressure, and Cardiovascular Disease
Intervention for High-normal Blood Pressure in Adults With Type 2 Diabetes
Research Evidence
Peer-reviewed studies linked via MeSH term "Diabetes Mellitus, Adult Onset" from the MEDLINE/PubMed database.
Research data from MEDLINE/PubMed
Signs & Symptoms
Based on Human Phenotype Ontology (HPO) disease-phenotype annotations.
Related Conditions
Quick Facts
- SNOMED CT
- 44054006
- UMLS CUI
- C0011860
- Fully Specified Name
- Diabetes mellitus type 2 (disorder)
- Specialists
- 3
- Diagnostic Biomarkers
- 4
- HPO Phenotypes
- 3
- Known Treatments
- 20
- Clinical Trials
- 903
Related Health Goals
This information is for educational purposes only and does not constitute medical advice, diagnosis, or treatment. Always consult with a qualified healthcare provider regarding any medical condition or treatment plan.
Clinical content is derived from the SNOMED CT clinical ontology and curated medical knowledge graphs.