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.

Last reviewed: 30 Nov 2025
Last updated: 12 Nov 2025

Summary

Definition

History and exam

Key diagnostic factors

  • hypotension
  • tachycardia
  • skin changes
  • oliguria
  • mental state changes
  • presence of risk factors
  • fever
  • chest pain
  • dyspnoea
  • hypoxaemia
  • hypothermia

Other diagnostic factors

  • abdominal pain
  • peripheral oedema
  • raised jugular venous pressure (JVP)
  • muffled or quiet heart sounds
  • arrhythmia
  • petechial rash
  • urticarial rash
  • angio-oedema
  • reduced breath sounds on one side of the chest
  • tracheal deviation
  • distended bladder
  • flaccid paralysis of the limbs

Risk factors

  • increasing age
  • comorbidities
  • myocardial infarction
  • cardiomyopathy
  • heart valve disease
  • arrhythmias
  • trauma
  • gastrointestinal bleeding
  • ruptured abdominal aortic aneurysm
  • burns
  • heat stroke
  • gastrointestinal losses: diarrhoea and vomiting
  • pancreatitis
  • sepsis
  • anaphylaxis/poisoning
  • spinal or brainstem injury
  • endocrine disease
  • pulmonary embolism
  • cardiac tamponade
  • medication induced

Diagnostic investigations

1st investigations to order

  • lactate
  • venous blood gas (VBG) or arterial blood gas (ABG)
  • glucose
  • full blood count
  • urea and electrolytes
  • coagulation studies
  • C-reactive protein
  • procalcitonin
  • ECG

Investigations to consider

  • chest x-ray
  • urinalysis and urine pregnancy test
  • infection screen
  • point-of-care ultrasound
  • CT chest, abdomen, and pelvis
  • computed tomographic pulmonary angiography (CTPA)
  • x-ray long bones
  • CT spine

Treatment algorithm

Contributors

Expert advisers

Jamie Scott, MB BAO, BCh, MSc

Emergency Medicine Consultant

Newham Hospital

Barts Health NHS Trust

Physician Response Unit Senior Fellow

London’s Air Ambulance

Royal London Hospital

UK

Flight Doctor

Essex and Herts Air Ambulance Trust

Disclosures

JS declares that he has no competing interests.

Acknowledgements

BMJ Best Practice would like to gratefully acknowledge the previous expert contributors, whose work has been retained in parts of the content:

Samuel J. Stratton MD, MPH

Professor

Fielding School of Public Health

David Geffen School of Medicine at UCLA

Los Angeles

Deputy Health Officer

Orange County Health Care Agency

Health Disaster Management/Emergency Medical Services

Santa Ana

CA

Alexander Alexiou MBBS, BSc, DCH, FRCEM, Dip IMC RCSEd

Emergency Medicine Consultant

Barts Health NHS Trust

Physician Response Unit Consultant

London’s Air Ambulance

Royal London Hospital

UK

Clovis Rau MBBS, BSc, FRCEM DipIMC

ST6 Emergency Medicine

Barnet Hospital

Royal Free NHS Foundation Trust

UK

Disclosures

SJS, AA, and CR declares that they have no competing interests.

Peer reviewers

Paul Frost

Reader (clinical)

Centre for Medical Education

School of Medicine

Cardiff University

Honorary Consultant in Intensive Care Medicine

University Hospital of Wales

Cardiff

UK

Disclosures

PF declares that he has no competing interests.

Michael Toolis, MBBS, FCICM, GDipClinUS

Consultant Intensivist

Monash Health

Melbourne

Australia

Disclosures

MT declares that he has no competing interests.

Peer reviewer acknowledgements

BMJ Best Practice topics are updated on a rolling basis in line with developments in evidence and guidance. The peer reviewers listed here have reviewed the content at least once during the history of the topic.

Disclosures

Peer reviewer affiliations and disclosures pertain to the time of the review.

References

Our in-house evidence and editorial teams collaborate with international expert contributors and peer reviewers to ensure that we provide access to the most clinically relevant information possible.

Key articles

Evans L, Rhodes A, Alhazzani W, et al. Surviving sepsis campaign: international guidelines for management of sepsis and septic shock 2021. Intensive Care Med. 2021 Nov;47(11):1181-247.Full text  Abstract

Cecconi M, De Backer D, Antonelli M, et al. Consensus on circulatory shock and hemodynamic monitoring: task force of the European Society of Intensive Care Medicine. Intensive Care Med. 2014 Dec;40(12):1795-815.Full text  Abstract

McDonagh TA, Metra M, Adamo M, et al. 2021 ESC guidelines for the diagnosis and treatment of acute and chronic heart failure. Eur Heart J. 2021 Sep 21;42(36):3599-726.Full text  Abstract

National Institute for Health and Care Excellence. Suspected sepsis: recognition, diagnosis and early management. Mar 2024 [internet publication].Full text

National Institute for Health and Care Excellence. Major trauma: assessment and initial management. Feb 2016 [internet publication].Full text

Reference articles

A full list of sources referenced in this topic is available here.

Use of this content is subject to our disclaimer