Type 2 diabetes in adults

Last reviewed: 24 Feb 2023
Last updated: 22 Feb 2022



History and exam

Key diagnostic factors

  • presence of risk factors
  • asymptomatic
  • polydipsia
  • polyuria
More key diagnostic factors

Other diagnostic factors

  • candidal infections
  • skin infections
  • urinary tract infections
  • fatigue
  • blurred vision
  • polyphagia
  • unintentional weight loss
  • paraesthesias
  • acanthosis nigricans
Other diagnostic factors

Risk factors

  • older age
  • overweight/obesity
  • gestational diabetes
  • non-diabetic hyperglycaemia
  • family history of type 2 diabetes
  • non-white ancestry
  • polycystic ovary syndrome
  • hypertension
  • dyslipidaemia
  • cardiovascular disease
  • stress
More risk factors

Diagnostic investigations

1st investigations to order

  • fasting plasma glucose
  • HbA1c
  • 2-hour post-load glucose after 75 g oral glucose
  • random plasma glucose
More 1st investigations to order

Investigations to consider

  • fasting lipid profile
  • urine ketones
  • albumin to creatinine ratio (ACR)
  • serum creatinine and estimated GFR
  • ECG
  • ankle-brachial pressure index (ABPI)
  • random C-peptide
  • autoantibody testing
  • liver function tests
More investigations to consider

Treatment algorithm


at initial diagnosis


metformin tolerated and not contraindicated: non-pregnant

metformin contraindicated or not tolerated: non-pregnant




Amar Puttanna, MBChB, MRCP

Diabetes and Endocrinology Consultant

Good Hope Hospital

University Hospitals Birmingham NHS Trust



AP has received honoraria from Napp, Novo Nordisk, Sanofi, Lilly-Boehringer Ingelheim, Daiichi-Sankyo, and AstraZeneca for presentation at meetings, conference registration or participating in advisory boards.

Partha Kar, OBE, MBBS MD, FRCP

Consultant Endocrinologist

Portsmouth Hospitals University NHS Trust

National Specialty Advisor, Diabetes, NHS England



PK has sat on advisory boards and attended events reimbursed by Novo Nordisk, Eli Lilly, and Sanofi.


Dr Amar Puttanna and Dr Partha Kar would like to gratefully acknowledge Dr Patrick J. O'Connor and Dr JoAnn M. Sperl-Hillen, the previous contributors to this topic.


PJO receives research funding from the National Institutes of Health on multiple projects and is an author of a number of references cited in this topic. JMS-H is an author of a number of references cited in this topic and 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.

Peer reviewers

Vinod Patel, MD, FRCP, FHEA, MRCGP, DRCOG, MBChB, BSc (Hons), RCPathME

Professor, Diabetes and Clinical Skills

Warwick Medical School

University of Warwick

Hon Consultant in Endocrinology and Diabetes, Acute Medicine, Medical Obstetrics

Diabetes and Endocrinology Centre

George Eliot Hospital NHS Trust


Clinical Director for Diabetes West Midlands Clinical Networks & Clinical Senate

NHS England and NHS Improvement - Midlands



VP declares he has worked with most of the large pharmaceutical industry groups over the years with the majority of the work being in education of healthcare professionals in diabetes care. This includes Novo Nordisk, Eli Lily, MSD, BI, Sanofi, Napp, Internis, Takeda, and AZ. VP has been part of advisory board work on occasions. VP has received conference arrangements and lecture fees. VP is a trustee of the charity South Asian Health Foundation.


Price-Evans Professor of Cardiovascular Medicine

University of Liverpool

Senior Investigator

National Institute for Health Research


Distinguished Professor

Faculty of Medicine

Aalborg University


Adjunct Professor

Yonsei University


South Korea


GL has acted as a consultant and speaker for BMS/Pfizer, Boehringer Ingelheim, and Daiichi-Sankyo.

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