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This guideline covers diagnosing and managing community- and hospital-acquired pneumonia in adults. It aims to improve accurate assessment and diagnosis of pneumonia to help guide antibiotic prescribing and ensure that people receive the right treatment.

Fluoroquinolone antibiotics: In March 2019, the MHRA issued restrictions and precautions for the use of fluoroquinolone antibiotics because of rare reports of disabling and potentially long-lasting or irreversible side effects (see Drug Safety Update for details). NICE is reviewing recommendations relating to fluoroquinolone antibiotics.

Presentation with lower respiratory tract infection

  • For people presenting with symptoms of lower respiratory tract infection in primary care, consider a point of care C-reactive protein test if after clinical assessment a diagnosis of pneumonia has not been made and it is not clear whether antibiotics should be prescribed. Use the results of the C-reactive protein test to guide antibiotic prescribing in people without a clinical diagnosis of pneumonia as follows:
    • Do not routinely offer antibiotic therapy if the C-reactive protein concentration is less than 20 mg/litre.
    • Consider a delayed antibiotic prescription (a prescription for use at a later date if symptoms worsen) if the C-reactive protein concentration is between 20 mg/litre and 100 mg/litre.
    • Offer antibiotic therapy if the C-reactive protein concentration is greater than 100 mg/ litre.

Community-acquired pneumonia

Severity assessment in primary care

  • When a clinical diagnosis of community-acquired pneumonia is made in primary care, determine whether patients are at low, intermediate or high risk of death using the CRB65 score (see box 1).

Box 1 CRB65 score for mortality risk assessment in primary care[a]

CRB65 score is calculated by giving 1 point for each of the following prognostic features:

  • confusion (abbreviated Mental Test score 8 or less, or new disorientation in person, place or time)[b]
  • raised respiratory rate (30 breaths per minute or more)
  • low blood pressure (diastolic 60 mmHg or less, or systolic less than 90 mmHg)
  • age 65 years or more.

Patients are stratified for risk of death as follows:

  • 0: low risk (less than 1% mortality risk)
  • 1 or 2: intermediate risk (1–10% mortality risk)
  • 3 or 4: high risk (more than 10% mortality risk).

[a] Lim WS, van der Eerden MM, Laing R, et al. (2003) Defining community-acquired pneumonia severity on presentation to hospital: an international derivation and validation study. Thorax 58: 377–82

[b] For guidance on delirium, see the NICE guideline on delirium.

  • Use clinical judgement in conjunction with the CRB65 score to inform decisions about whether patients need hospital assessment as follows:
    • consider home-based care for patients with a CRB65 score of 0
    • consider hospital assessment for all other patients, particularly those with a CRB65 score of 2 or more.

Microbiological tests

  • Do not routinely offer microbiological tests to patients with low-severity community-acquired pneumonia.
  • For patients with moderate- or high-severity community-acquired pneumonia:
    • take blood and sputum cultures and
    • consider pneumococcal and legionella urinary antigen tests.

Antibiotic therapy

See the NICE guideline on pneumonia (community-acquired): antimicrobial prescribing for recommendations on antibiotic therapy.

Glucocorticoid treatment

  • Do not routinely offer a glucocorticoid to patients with community-acquired pneumonia unless they have other conditions for which glucocorticoid treatment is indicated.

Patient Information

  • Explain to patients with community-acquired pneumonia that after starting treatment their symptoms should steadily improve, although the rate of improvement will vary with the severity of the pneumonia, and most people can expect that by:
    • 1 week: fever should have resolved
    • 4 weeks: chest pain and sputum production should have substantially reduced
    • 6 weeks: cough and breathlessness should have substantially reduced
    • 3 months: most symptoms should have resolved but fatigue may still be present
    • 6 months: most people will feel back to normal.
  • Advise patients with community-acquired pneumonia to consult their healthcare professional if they feel that their condition is deteriorating or not improving as expected.

Hospital-acquired pneumonia


© NICE 2019. Pneumonia in adults: diagnosis and management. Available from: www.nice.org.uk/guidance/cg191. All rights reserved. Subject to Notice of rights.

NICE guidance is prepared for the National Health Service in England. All NICE guidance is subject to regular review and may be updated or withdrawn. NICE accepts no responsibility for the use of its content in this product/publication.

Published date: 03 December 2014.

Last updated: 16 September 2019 (reinstated 07 July 2022).