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Last reviewed: 1 Aug 2025
Last updated: 25 Mar 2025

Summary

Definition

History and exam

Key diagnostic factors

  • acute or chronic cough
  • fever
  • dyspnea
  • wheezing
  • crackles

Risk factors

  • decreased level of consciousness (Glasgow coma scale score <9)
  • increased severity of illness
  • general anesthesia
  • age >70 years
  • male sex
  • head trauma
  • cerebrovascular disease
  • endotracheal or tracheostomy tube
  • dysphagia
  • airway difficulties
  • barium meal
  • gastroesophageal reflux disease
  • feeding tubes
  • supine position
  • delayed gastric emptying
  • obesity
  • drugs that reduce esophageal sphincter tone

Diagnostic tests

Tests to consider

  • chest CT
  • bronchoscopy with bronchoalveolar lavage
  • CBC
  • arterial blood gases
  • blood culture
  • thoracentesis

Treatment algorithm

Contributors

Authors

Professor of Medicine

Division of Pulmonary and Critical Care Medicine

Mayo Clinic Florida

Jacksonville

FL

Disclosures

AL declares that he has no competing interests.

Fellow

Division of Pulmonary and Critical Care Medicine

Mayo Clinic Florida

Jacksonville

FL

Disclosures

SD declares that he has no competing interests.

Dr Augustine Lee and Dr Spencer Deleveaux would like to gratefully acknowledge Dr Madison Macht, Dr Kamran Mahmood, Dr Scott Shofer, Dr Septimiu Murgu, and Dr Henri Colt, previous contributors to this topic.

Disclosures

MM, KM, SS, SM, and HC declare they have no competing interests.

Peer reviewers

Clinical Director

Acute Medicine

Associate Medical Director

Consultant Emergency Medicine

Guy's and St Thomas' NHS Foundation Trust

Clinical Lead and Consultant

Accident and Emergency Medicine

St Thomas' Hospital

London

UK

Disclosures

AP declares that he has no competing interests.

Director

Interventional Pulmonology

Division of Pulmonary, Allergy, and Critical Care Medicine

Assistant Professor of Medicine

Duke University Medical Center

Durham

NC

Disclosures

MMW declares that he has no competing interests.

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

Marik PE. Aspiration pneumonitis and aspiration pneumonia. N Engl J Med. 2001 Mar 1;344(9):665-71. Abstract

Smith Hammond CA, Goldstein LB. Cough and aspiration of food and liquids due to oral-pharyngeal dysphagia: ACCP evidence-based clinical practice guidelines. Chest. 2006 Jan;129(1 suppl):154S-68S.Full text  Abstract

American Society of Anesthesiologists. Practice guidelines for preoperative fasting and the use of pharmacologic agents to reduce the risk of pulmonary aspiration: application to healthy patients undergoing elective procedures - an updated report by the American Society of Anesthesiologists task force on preoperative fasting and the use of pharmacologic agents to reduce the risk of pulmonary aspiration. Anesthesiology. 2017 Mar;126(3):376-93.Full text  Abstract

Reference articles

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

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