Glasgow-Blatchford Score Calculator

Glasgow-Blatchford Score Calculator for Gastroenterology. A total of 0-1 is a very-low-risk range in the cited ACG pathway, but outpatient care also requires clinical stability, no other admission indication and reliable follow-up. Higher totals do not prescribe endoscopy timing.

For shared guidance on choosing a tool and documenting results, read the clinical calculator workflow.

How this calculator works

GBS adds pretreatment urea, one sex-specific hemoglobin contribution, blood pressure, pulse and four clinical features. Maximum 23. Urea thresholds are 6.5, 8, 10 and 25 mmol/L; values at a threshold enter the higher band.

When to use this calculator

Use within an adult acute upper gastrointestinal bleeding pathway after initial clinical assessment. Active hemorrhage or instability requires immediate care regardless of the score.

Inputs used

  • Urea (mmol/L; not BUN mg/dL)
  • Hemoglobin (g/dL)
  • Sex used by the original hemoglobin model
  • Systolic pressure (mmHg)
  • Pulse (/min)
  • Melena
  • Syncope
  • Known hepatic disease
  • Cardiac failure

Clinical interpretation

A total of 0-1 is a very-low-risk range in the cited ACG pathway, but outpatient care also requires clinical stability, no other admission indication and reliable follow-up. Higher totals do not prescribe endoscopy timing.

Worked example

Fictional teaching case. Urea (mmol/L; not BUN mg/dL): 8; Hemoglobin (g/dL): 11; Sex used by the original hemoglobin model: Male; Systolic pressure (mmHg): 105; Pulse (/min): 110; Melena: Yes; Syncope: No; Known hepatic disease: No; Cardiac failure: No. Result: 9 points. Above the very-low-risk score range. Contributions in assessment order: 3 + 3 + 1 + 1 + 1 + 0 + 0 + 0 = 9. Outpatient care is considered only after clinical assessment, other admission indications and follow-up access. Active bleeding or instability requires urgent care regardless of total.

Limitations and safety notes

Use pre-endoscopy assessment in overt upper GI bleeding. Missing findings are not negative. A total above 1 is not an automatic endoscopy-timing or admission order.

Frequently asked questions

Can a GBS of 1 be treated as automatically high risk?

No. The ACG very-low-risk pathway includes selected patients with 0-1, but discharge still needs clinical judgment and an appropriate follow-up plan.

What can change the meaning of this result?

Use pre-endoscopy assessment in overt upper GI bleeding. Missing findings are not negative. A total above 1 is not an automatic endoscopy-timing or admission order.

References

  • Original GBS derivation and inputs. https://pubmed.ncbi.nlm.nih.gov/11073021/
  • ACG upper GI bleeding guidance, very-low-risk score 0-1. https://pubmed.ncbi.nlm.nih.gov/33929377/
  • NICE upper GI bleeding guideline context. https://www.nice.org.uk/guidance/cg141
  • NHS GGC original local clinical guidance table verifies urea, hemoglobin and hemodynamic bands. https://handbook.ggcmedicines.org.uk/guidelines/gastrointestinal-system/glasgow-blatchford-score/

Editorial review and citation methodology

Maintained by the Quick Medical Calculator Editorial Team. Content record date: September 9, 2026. A content date is not evidence of independent clinical review. Individual clinical sign-off is not recorded on this page.

  • Prefer original validation studies for scoring systems and prediction tools.
  • Use current specialty society guidance, transplant allocation policy, public health guidance, or regulator resources when they govern clinical use.
  • Include limitations and safety notes when a calculator is population-specific, context-dependent, or unsuitable as a standalone decision tool.

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