Physical Exam

Respiratory Rate

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Video coming September 2026

How to Perform

Without alerting the patient (ideally while appearing to take the pulse, so breathing is not consciously altered), count the breaths over a full 60 seconds by watching or feeling the chest or abdomen rise.

How to Interpret

Pneumonia

Tachypnea (respiratory rate ≥20 breaths per minute)

Rule in

Somewhat helpful

Rule out

—

Evidence:Strong

Pulmonary Embolism

Tachypnea (respiratory rate >20 breaths per minute)

Rule in

—

Rule out

Minimally helpful

Evidence:Limited

References

Htun TP, Sun Y, Chua HL, Pang J. Clinical features for diagnosis of pneumonia among adults in primary care setting: A systematic and meta-review. Sci Rep. 2019;9(1):7600. doi:10.1038/s41598-019-44145-y. PMID: 31110214. PMC: PMC6527561. Open access. PRISMA-compliant systematic review with QUADAS-2 quality assessment. 13 included studies (n=11,144 total adult participants in primary care, outpatient, and emergency department settings). 7 included studies contributed to the respiratory rate pooled estimate at the ≥20 breaths-per-minute threshold. Reference standard for pneumonia: chest radiograph in 13 studies.
Modern guideline references: Singer M, Deutschman CS, Seymour CW, et al. The Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3). JAMA. 2016;315(8):801-810. doi:10.1001/jama.2016.0287. PMID: 26903338. PMC: PMC4968574. qSOFA derivation/validation: Seymour CW, Liu VX, Iwashyna TJ, et al. Assessment of Clinical Criteria for Sepsis: For the Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3). JAMA. 2016;315(8):762-774. doi:10.1001/jama.2016.0288. PMID: 26903335. Pre-2016 SIRS reference: Bone RC, Balk RA, Cerra FB, et al. Definitions for sepsis and organ failure and guidelines for the use of innovative therapies in sepsis. ACCP/SCCM Consensus Conference Committee. Chest. 1992;101(6):1644-55. doi:10.1378/chest.101.6.1644. PMID: 1303622.
West J, Goodacre S. The value of clinical features in the diagnosis of acute pulmonary embolism: systematic review and meta-analysis. QJM. 2007;100(12):763-769. PMID: 18089542.
Wang CS, FitzGerald JM, Schulzer M, Mak E, Ayas NT. Does this dyspneic patient in the emergency department have congestive heart failure? JAMA. 2005;294(15):1944-1956. doi:10.1001/jama.294.15.1944. PMID: 16234501. (JAMA Rational Clinical Examination original article. Full PDF behind JAMA Network paywall, AMA membership renewal pending; abstract examined this session.) Modern classical-teaching references: Bickley LS. Bates' Guide to Physical Examination and History Taking. 13th ed. Wolters Kluwer; 2020. Sapira JD. The Art and Science of Bedside Diagnosis. 4th ed. (LeBlond/Brown/DeGowin eds.) Wolters Kluwer; 2014. Modern HF guideline: Heidenreich PA, Bozkurt B, Aguilar D, et al. 2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure. Circulation. 2022;145(18):e895-e1032. PMID: 35363499.
Historical primary reference: Cushing H. Concerning a definite regulatory mechanism of the vasomotor centre which controls blood pressure during cerebral compression. Johns Hopkins Hosp Bull. 1901;12:290-292. (Original observation including respiratory irregularity.) Modern guideline reference: Carney N, Totten AM, OReilly C, et al. Guidelines for the Management of Severe Traumatic Brain Injury, Fourth Edition. Neurosurgery. 2017;80(1):6-15. doi:10.1227/NEU.0000000000001432. PMID: 27654000. (Brain Trauma Foundation guidelines.) Modern physiologic review (open access): Wan WH, Ang BT, Wang E. The Cushing Response: a case for a review of its role as a physiological reflex. J Clin Neurosci. 2008;15(3):223-228. doi:10.1016/j.jocn.2007.05.025. PMID: 18182296. Respiratory-pattern teaching reference: Plum F, Posner JB. The Diagnosis of Stupor and Coma. 4th ed. Oxford University Press; 2007.
Historical primary reference: Kussmaul A. Zur Lehre vom Diabetes mellitus. Über eine eigentümliche Todesart bei Diabetischen, über Acetonämie, Glycerin-Behandlung des Diabetes und Einspritzungen von Diastase ins Blut bei dieser Krankheit. Deutsches Archiv für Klinische Medizin. 1874;14:1-46. (Original 1874 description of the respiratory pattern in DKA.) Modern DKA guideline references: American Diabetes Association. Standards of Care in Diabetes — 2024. Diabetes Care. 2024;47(Suppl 1). (DKA diagnostic criteria.) Kitabchi AE, Umpierrez GE, Miles JM, Fisher JN. Hyperglycemic crises in adult patients with diabetes. Diabetes Care. 2009;32(7):1335-43. doi:10.2337/dc09-9032. PMID: 19564476. PMC: PMC2699725. (Joint ADA/AACE consensus on hyperglycemic crises including DKA.) Classical-teaching reference: Bickley LS. Bates' Guide to Physical Examination and History Taking. 13th ed. Wolters Kluwer; 2020. Sapira JD. The Art and Science of Bedside Diagnosis. 4th ed. (LeBlond/Brown/DeGowin eds.) Wolters Kluwer; 2014.
Modern guideline / consensus references: American Heart Association. 2020 Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care: Part 4. (Opioid overdose response algorithm.) Boyer EW. Management of opioid analgesic overdose. N Engl J Med. 2012;367(2):146-55. doi:10.1056/NEJMra1202561. PMID: 22784117. (Review of opioid-overdose pathophysiology and management.) DSM-5-TR diagnostic criteria for opioid intoxication: American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition Text Revision (DSM-5-TR). 2022. Classical-teaching reference: Goldfrank's Toxicologic Emergencies. 11th ed. McGraw Hill; 2019. (Opioid chapter.) Naloxone evidence and dose-finding: Wermeling DP. Review of naloxone safety for opioid overdose. Ther Adv Drug Saf. 2015;6(1):20-31. PMID: 25642320. PMC: PMC4308412.
McGee S. Evidence-Based Physical Diagnosis. 6th ed. Philadelphia, PA: Elsevier; 2025.