Type 1 diabetes mellitus
Summary
Definition
History and exam
Key diagnostic factors
- polyuria
- polydipsia
- diabetic ketoacidosis
Other diagnostic factors
- young age
- weight loss
- blurred vision
- nausea and vomiting
- abdominal pain
- tachypnea
- clinical dehydration
- lethargy
- altered mental status
Risk factors
- genetic predisposition
- geographic region
- infectious agents
- dietary factors
- use of immunotherapy
Diagnostic investigations
1st investigations to order
- HbA1c
- fasting plasma glucose
- 2-hour post-glucose load plasma glucose
- random plasma glucose
Investigations to consider
- plasma or urine ketones
- random C-peptide
- autoimmune markers
Treatment algorithm
nonpregnant
pregnant
Contributors
Authors
Rajesh K. Garg, MD
Professor of Medicine
David Geffen School of Medicine at UCLA
Harbor-UCLA Medical Center
Torrance
CA
Disclosures
RKG is an author of a number of references cited in this topic.
Acknowledgements
Dr Rajesh K. Garg would like to gratefully acknowledge Dr Varsha Vimalananda, previous contributor to this topic.
Disclosures
VV declares that she has no competing interests.
Peer reviewers
Zachary Bloomgarden, MD
Clinical Professor
Medicine/Endocrinology
Diabetes and Bone Disease
Mount Sinai School of Medicine
New York
NY
Disclosures
ZB declares that he has no competing interests.
Alicia Jenkins, MB, BS, MD, FRACP, FRCP
Associate Professor
Department of Medicine
University of Melbourne
Melbourne
Australia
Professor
Harold Hamm Oklahoma Diabetes Center
University of Oklahoma Health Sciences Center
Oklahoma City
OK
Divulgaciones
AJ has been a (non-salaried) co-investigator on multi-center clinical trials supported by Novo, Eli Lilly, Sanofi-Aventis, and Medtronic. She does not hold any stocks or shares in these companies. She has received a speaker's honorarium from Novo Nordisk.
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Referencias
Artículos principales
American Diabetes Association. Standards of care in diabetes - 2025. Diabetes Care. 2025 Jan;48(1):S344-52.Texto completo
Norris JM, Johnson RK, Stene LC. Type 1 diabetes-early life origins and changing epidemiology. Lancet Diabetes Endocrinol. 2020 Mar;8(3):226-38.Texto completo Resumen
International Society for Pediatric and Adolescent Diabetes. ISPAD clinical practice consensus guidelines 2024. Dec 2024 [nternet publication].Texto completo
Holt RIG, DeVries JH, Hess-Fischl A, et al. The management of type 1 diabetes in adults. A consensus report by the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD). Diabetologia. 2021 Dec;64(12):2609-52.Texto completo Resumen
Artículos de referencia
Una lista completa de las fuentes a las que se hace referencia en este tema está disponible para los usuarios con acceso a todo BMJ Best Practice.
Diferenciales
- Monogenic diabetes: maturity onset diabetes of the young
- Monogenic diabetes: neonatal diabetes mellitus
- Type 2 diabetes
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