What does each CURB-65 letter stand for?

C = Confusion (new disorientation), U = Urea > 7 mmol/L (BUN > 19 mg/dL), R = Respiratory rate ≥ 30 breaths/min, B = Blood pressure (systolic < 90 mmHg or diastolic ≤ 60 mmHg), 65 = Age ≥ 65 years. Each criterion scores 1 point (maximum 5).

What do the CURB-65 score ranges mean clinically?

Score 0–1: low risk, 30-day mortality ~1–2%, consider outpatient treatment. Score 2: moderate risk, ~9% mortality, consider short hospital stay. Score 3–5: high risk, 15–40% mortality, hospitalization with consideration of ICU for score ≥ 4.

What is the GOLD classification for COPD?

GOLD grades are based on post-bronchodilator FEV1% predicted: GOLD 1 (mild) ≥ 80%, GOLD 2 (moderate) 50–79%, GOLD 3 (severe) 30–49%, GOLD 4 (very severe) < 30%. Higher grades indicate more airflow limitation and typically require intensified therapy.

Can I use urea in mg/dL instead of mmol/L?

Yes — the threshold 7 mmol/L equals approximately 19 mg/dL. If your lab reports BUN (blood urea nitrogen), a BUN > 19 mg/dL is roughly equivalent. The calculator accepts mmol/L; convert BUN by dividing mg/dL by 2.8 if needed.

Is this calculator a substitute for clinical judgment?

No. CURB-65 and GOLD are decision-support tools. Patient comorbidities, social circumstances, clinical trajectory, and local protocols must always inform the final decision. Always defer to your institutional guidelines and senior clinicians.

CURB-65 / COPD Severity Calculator

Name: CURB-65 / COPD Severity Calculator
Availability: InStock
Author: Nham Vu

Score community-acquired pneumonia severity with CURB-65 and classify COPD stage using the GOLD FEV1% framework.

CURB-65 Criteria

Check each criterion that applies to the patient. Each scores 1 point.

C — Confusion

New onset disorientation to person, place, or time

U — Urea > 7 mmol/L

Blood urea nitrogen > 19 mg/dL (BUN equivalent)

R — Respiratory Rate ≥ 30 /min

Measured at rest

B — Low Blood Pressure

Systolic < 90 mmHg or diastolic ≤ 60 mmHg

65 — Age ≥ 65 years

Patient is 65 years old or older

Result

out of 5

Low Risk

30-day mortality: ~1–2%

LowModerateSevere

Recommended Management

Score 0–1: Low risk. Consider outpatient treatment with oral antibiotics and close follow-up.

Score Breakdown

0–1 Low

2 Moderate

3–5 Severe

FEV1 % Predicted

Enter the patient's post-bronchodilator FEV1 as a percentage of the predicted value.

FEV1 % predicted

Note: GOLD classification applies only to patients with confirmed airflow limitation (post-bronchodilator FEV1/FVC < 0.70). This tool does not replace spirometry interpretation.

Quick Reference

≥ 80% GOLD 1 — Mild

50–79% GOLD 2 — Moderate

30–49% GOLD 3 — Severe

< 30% GOLD 4 — Very Severe

Result

Enter FEV1 % to see the GOLD classification

Clinical Disclaimer: This tool is intended for educational and decision-support purposes only. It does not replace clinical judgment, full patient assessment, or local clinical guidelines. Always verify results against primary literature and consult senior clinicians for patient management decisions.

Summary

Score community-acquired pneumonia severity with CURB-65 and classify COPD stage using the GOLD FEV1% framework.

How it works

Select the CURB-65 tab and tick whichever of the five criteria apply to the patient.
The score (0–5) updates instantly with a risk category (low, moderate, or severe) and management guidance.
Switch to the GOLD COPD tab and enter the patient's post-bronchodilator FEV1% predicted.
The tool classifies the result as GOLD 1 (mild) through GOLD 4 (very severe) with an explanation.
Review the management notes and consult your local clinical guidelines for final disposition.

Use cases

Emergency physicians triaging patients with suspected community-acquired pneumonia.
Hospitalists deciding between outpatient, ward, or ICU admission for CAP.
Respiratory specialists staging COPD severity for treatment escalation.
Primary care clinicians monitoring a patient's COPD trajectory over time.
Medical students and trainees learning pneumonia and COPD scoring systems.
Nursing staff quickly communicating severity to covering physicians.

Frequently Asked Questions

Last updated: 2026-06-09 · Reviewed by Nham Vu