Adults with CAP
Use after clinical assessment
CURB-65 Pneumonia Severity
Five clinical criteria. A clear score. Context for clinical judgment.
Urea result required
Unknown is not the same as No
Bedside observations
Use current clinical findings
CURB-65 SCORE
/ 5
Awaiting findings30-day mortality band
—
NICE grouped estimate · not an individual prediction
Assess all five criteria to see the score and clinical context.
A low score does not rule out serious illness.
0–1Low2Intermediate3–5High
The score is only part of the picture
Oxygenation, sepsis, comorbidities and ability to manage at home also matter.
Critical-care decisions require additional criteria and clinical judgment.
Illustration only · not a diagnostic image.
Interpreting the risk bands
| CURB-65 score | Risk group | 30-day mortality (NICE) |
|---|---|---|
| 0–1 | Low | <3% |
| 2 | Intermediate | 3–15% |
| 3–5 | High | >15% |
Group estimates vary by cohort; these are not patient-specific probabilities.
ATS/IDSA favors PSI plus clinical judgment for admission decisions.
Criteria, units & limitations
One point is assigned to each positive criterion. New confusion means new disorientation in person, place or time, or an Abbreviated Mental Test (AMT) score of 8 or less.
The original laboratory criterion is urea strictly greater than 7 mmol/L. This corresponds to a BUN threshold of approximately 19.6 mg/dL; urea and BUN in mg/dL are not interchangeable. The equality boundary at urea 7 mmol/L is not positive.
Respiratory rate ≥30/min and age ≥65 are inclusive. Low blood pressure means systolic <90 mmHg OR diastolic ≤60 mmHg; either condition scores one point, not two.
CURB-65 supports initial hospital assessment of adults with community-acquired pneumonia. It does not diagnose pneumonia, choose antibiotics or determine the need for intensive care. It omits oxygen saturation, comorbidities and social circumstances. A clinician may escalate care at any score.
These are NICE grouped mortality bands, not the score-specific rates from a different study. Do not compare them as if they were individualized probabilities.
Frequently asked questions
Who is CURB-65 for?
Adults with clinically diagnosed community-acquired pneumonia, assessed with clinical judgment, usually at presentation to hospital. It is not a self-diagnosis tool and is not the validated pediatric or hospital-acquired pneumonia assessment.
What if the urea result is missing?
Leave the urea criterion unanswered. This page will not produce a complete CURB-65 score or assume that the result is normal. A clinician may use the separate CRB-65 approach when appropriate; its range and risk interpretation differ and must not be substituted here.
Does a low score mean discharge is safe?
No. Oxygenation, sepsis, comorbidities, oral intake, frailty and the ability to manage safely at home also matter. Outpatient care is a clinician-led consideration, not an automatic recommendation from this calculator. Severe breathing difficulty or rapid deterioration requires emergency help regardless of the score.
Does a high score mandate intensive care?
No. Scores 3–5 indicate high mortality risk and support urgent hospital assessment. Critical-care referral depends on the full clinical picture and additional severity criteria. Mechanical ventilation or vasopressor requirements and other severe CAP findings need their own assessment.
Sources & References
NICENICEPneumonia guideline NG250Community-acquired pneumonia in adults.
IDSAATS / IDSAAdult CAP clinical guidanceDiagnosis and management of adults with pneumonia.ThoraxLim et al. (2003)Original validation studyDevelopment and validation of a bedside score (CURB-65).
IDSAATS / IDSAAdult CAP clinical guidanceDiagnosis and management of adults with pneumonia.ThoraxLim et al. (2003)Original validation studyDevelopment and validation of a bedside score (CURB-65).Clinical decision support only. Official guideline wording and permissions remain with their rights holders. References do not imply endorsement.
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Five clinical criteria. A clear score. Context for clinical judgment.