When viewing this topic in a different language, you may notice some differences in the way the content is structured, but it still reflects the latest evidence-based guidance.

Type 2 diabetes mellitus in adults

Last reviewed: 11 Nov 2024
Last updated: 04 Dec 2024

Summary

Definition

History and exam

Key diagnostic factors

  • asymptomatic
  • polydipsia
  • polyuria
  • unintentional weight loss
  • polyphagia
  • hyperglycemic crisis
Full details

Other diagnostic factors

  • fatigue
  • blurred vision
  • nocturia
  • candidal infections
  • skin infections
  • urinary tract infections
  • paresthesias
  • acanthosis nigricans
Full details

Risk factors

  • older age
  • overweight/obesity
  • gestational diabetes
  • prediabetes
  • first-degree relative with type 2 diabetes
  • African, Latino, Asian or American-Indian ancestry
  • physical inactivity
  • polycystic ovary syndrome (PCOS)
  • hypertension
  • dyslipidemia
  • cardiovascular disease
  • stress
  • smoking
Full details

Diagnostic tests

1st tests to order

  • HbA1c
  • fasting plasma glucose
  • 2-hour plasma glucose
  • random plasma glucose
Full details

Tests to consider

  • urine ketones
  • random C-peptide
  • autoantibodies
  • urinary albumin excretion
  • serum creatinine and estimated GFR (eGFR)
  • fasting lipid profile
  • ECG
  • ankle-brachial index (ABI)
  • toe-brachial index (TBI)
  • dilated retinal examination
  • liver function test (LFT)
  • CBC
  • noninvasive tests of liver elasticity
Full details

Treatment algorithm

INITIAL

at initial diagnosis

ACUTE

marked hyperglycemia nonpregnant: serum glucose ≥300 mg/dL (≥16.7 mmol/L) or HbA1c >10% (>86 mmol/mol) or symptomatic

without marked hyperglycemia nonpregnant asymptomatic: serum glucose <300 mg/dL (<16.7 mmol/L) or HbA1c <10% (<86 mmol/mol)

pregnant

Contributors

Authors

Gregg Simonson, PhD

Director Professional Training

International Diabetes Center at Park Nicollet

Minneapolis

MN

Disclosures

GS declares that his employer, HealthPartners Institute dba International Diabetes Center, has organizational interests that include receiving unrestricted educational grants from Abbott Diabetes Care and Sanofi. GS receives no personal income from any of these activities.

Anders Carlson, MD

Medical Director

International Diabetes Center at Park Nicollet

Minneapolis

MN

Disclosures

AC is employed by HealthPartners Institute and Fabric. HealthPartners Institute has received payments on AC's behalf for research and/or consulting services from Abbott Diabetes, Dexcom, Eli Lilly, Novo Nordisk, Sanofi, Medtronic, Insulet, Tandem Diabetes, Mannkind, and United Health Group. All research or consulting fees are paid directly to HealthPartners Institute. AC receives no personal income from any of these services. AC is an author of a number of references cited in this topic.

Thomas Martens, MD

Medical Director

International Diabetes Center at Park Nicollet

Minneapolis

MN

Disclosures

HealthPartners Institute employs TM and has contracts with Abbott Diabetes Care, Dexcom, Insulet, Eli Lilly, Medtronic, Novo Nordisk, Sanofi US Services, Inc., and Tandem for his services as a research investigator, speaker, and/or consultant. No personal income from any of these services goes to TM. TM is an author of a number of references cited in this topic.

Richard Bergenstal, MD

Executive Director

International Diabetes Center at Park Nicollet

Minneapolis

MN

Disclosures

RB has received research support, has acted as a consultant, or has been on the scientific advisory board for Abbott Diabetes Care, Ascensia, Bigfoot Biomedical, Inc., CeQur, DexCom, Eli Lilly, Hygieia, Insulet, Medtronic, Novo Nordisk, Onduo, Roche Diabetes Care, Tandem Diabetes Care, Sanofi, United Healthcare, Vertex Pharmaceuticals, and Zealand Pharma. RB's employer, nonprofit HealthPartners Institute, contracts for his services and he receives no personal income. RB is an author of a number of references cited in this topic.

Acknowledgements

Dr Gregg Simonson, Dr Anders Carlson, Dr Thomas Martens, and Dr Richard Bergenstal would like to gratefully acknowledge Dr Patrick J. O'Connor and Dr JoAnn M. Sperl-Hillen, previous contributors to this topic.

Disclosures

PJO receives research funding from the National Institutes of Health on multiple projects. JMS-H is an inventor on a US patent for Disease Treatment Simulation, a simulation-based technology developed without commercial support to educate health providers on chronic disease management in a virtual environment. PJO and JMS-H are authors of a number of references cited in this topic.

Peer reviewers

David K. McCulloch, MD

Medical Director

Clinical Improvement Group Health Cooperative

Seattle

WA

Disclosures

DKM declares that he has no competing interests.

Ashim K. Sinha, MBBS, MD, FRACP, FACE

Associate Professor

Director of Diabetes and Endocrinology

Cairns Base Hospital and Diabetes Centre

Queensland

Australia

Disclosures

AKS declares that he has no competing interests.

  • Type 2 diabetes mellitus in adults images
  • Differentials

    • Prediabetes
    • Diabetes mellitus, type 1
    • Latent autoimmune diabetes in adults (LADA)
    More Differentials
  • Guidelines

    • ACOG clinical practice update: screening for gestational and pregestational diabetes in pregnancy and postpartum
    • Newer pharmacologic treatments in adults with type 2 diabetes
    More Guidelines
  • Patient information

    Prediabetes

    Diabetes: what is it?

    More Patient information
  • Calculators

    Glomerular Filtration Rate Estimation (eGFR) by Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) Equation with Creatinine, without Race (2021)

    Cirrhosis probability in hepatitis C (FIB-4)

    More Calculators
  • padlock-lockedLog in or subscribe to access all of BMJ Best Practice

Use of this content is subject to our disclaimer