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Last reviewed: 16 Mar 2025
Last updated: 23 Apr 2024

Summary

Definition

History and exam

Key diagnostic factors

  • presence of risk factors for hyperglycaemia
  • presence of risk factors for hypoglycaemia
  • history of diabetes mellitus
  • severe intercurrent illness or infection (hyperglycaemia)
  • insulin use (hypoglycaemia)
  • reduced level of consciousness/coma (hypoglycaemia and hyperglycaemia)
  • sweating (hypoglycaemia)
  • tachycardia (hypoglycaemia)
  • unusual behaviour (hypoglycaemia)

Other diagnostic factors

  • history of recent corticosteroid use
  • signs of diabetic retinopathy
  • signs of diabetic neuropathy
  • polyuria, polydipsia, or unintentional weight loss

Risk factors

  • severe illness (hyperglycaemia or hypoglycaemia)
  • corticosteroid use (hyperglycaemia)
  • poorly controlled diabetes mellitus (hyperglycaemia)
  • insulin administration or insulin secretagogues (hypoglycaemia)
  • changes to corticosteroid or insulin regimen (hypoglycaemia or hyperglycaemia)
  • poor nutritional intake (hypoglycaemia)
  • older age or cognitive impairment (hypoglycaemia)

Diagnostic investigations

1st investigations to order

  • random plasma glucose
  • HbA1c
  • serum urea, creatinine, and eGFR
  • spot urine albumin/creatinine ratio
  • serum ketones

Investigations to consider

  • post-discharge fasting plasma glucose or HbA1c
  • post-discharge 2-hour post-load glucose after 75 g oral glucose

Treatment algorithm

Contributors

Authors

M. Cecilia Lansang, MD, MPH
M. Cecilia Lansang

Professor of Medicine

Director of Endocrinology, Main Campus

Department of Endocrinology, Diabetes and Metabolism

Cleveland Clinic

Cleveland

OH

Disclosures

MCL has received research support from Dexcom, Xeris, and Abbott. She is also a consultant at Glooko.

Keren Zhou, MD

Clinical Assistant Professor of Medicine

Research Director, Endocrinology and Metabolism Institute

Department of Endocrinology, Diabetes and Metabolism

Cleveland Clinic

Cleveland

OH

Disclosures

KZ declares that she has no competing interests.

Acknowledgements

Dr M. Cecilia Lansang and Dr Keren Zhou would like to gratefully acknowledge Dr Suzanne Quinn, Dr Ajay Rao, and Dr Vivian Fonseca, previous contributors to this topic.

Disclosures

SQ, AR, and VF declare that they have no competing interests.

Peer reviewers

Guillermo E. Umpierrez, MD

Professor of Medicine

Division of Endocrinology

Metabolism and Lipids

Emory University School of Medicine

Atlanta

GA

Disclosures

GEU is an author of a number of references cited in this monograph.

Daniel Morganstein, MBBS, MA (Cantab), MRCP, PhD

Consultant Diabetologist

Beta Cell Unit

Chelsea and Westminster NHS Trust

London

UK

Disclosures

DM declares that he has no competing interests.

Sean Dinneen, MBBCh, FRCPI, FACP

Senior Lecturer in Medicine

National University of Ireland

Consultant in Diabetes and Endocrinology

Galway University Hospitals

Galway

Ireland

Disclosures

SD declares that he has no competing interests.

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