Glasgow-Blatchford Score Calculator
Risk-stratify a patient with a suspected upper gastrointestinal bleed using the Glasgow-Blatchford score (GBS). It combines blood urea, haemoglobin, systolic blood pressure, pulse and a few clinical findings into a total from 0 to 23. A score of 0 identifies very-low-risk patients who may be suitable for outpatient management, while higher scores predict a greater need for intervention such as transfusion or endoscopy. Enter the values below.
About the Glasgow-Blatchford score
The Glasgow-Blatchford score predicts the need for intervention in upper gastrointestinal bleeding from admission data alone, supporting safe triage before endoscopy. Source: Blatchford O, Murray WR, Blatchford M, “A risk score to predict need for treatment for upper-gastrointestinal haemorrhage,” The Lancet 2000;356(9238):1318–1321.
Frequently asked questions
What does the Glasgow-Blatchford score measure?
The Glasgow-Blatchford score predicts the need for clinical intervention — blood transfusion, endoscopic treatment or surgery — in a patient presenting with an upper gastrointestinal bleed, using only readily available admission data. It does not need an endoscopy to calculate, which is why it is widely used for triage in the emergency department. It was derived by Blatchford and colleagues and published in The Lancet in 2000. The output is a total from 0 to 23, and it is the low end of that range, not the high end, that carries the decision.
What is a low-risk score?
A score of 0 identifies very-low-risk patients who can often be managed as outpatients with early endoscopy, and some guidance extends this low-risk group to a score of 0 or 1. Any higher score generally means admission, because the likelihood of needing an intervention rises with the score. Local pathways vary.
What goes into the score?
The Glasgow-Blatchford score uses blood urea and haemoglobin (with sex-specific thresholds), systolic blood pressure, and points for a pulse of 100/min or more, melaena, syncope, and a history of liver disease or heart failure. The maximum is 23. The urea and haemoglobin bands, not simple yes/no answers, carry most of the weight.
What units does the calculator use?
For the Glasgow-Blatchford score, blood urea is entered in mmol/L (the UK convention) and haemoglobin in g/dL. If your urea is reported as blood urea nitrogen (BUN) in mg/dL, divide by 2.8 to get urea in mmol/L. If haemoglobin is in g/L, divide by 10 to get g/dL.
Is the score a substitute for clinical judgement?
The Glasgow-Blatchford score is not a substitute for clinical judgement. It is a validated triage aid that should be combined with the whole clinical picture, resuscitation status and local protocols. A low score does not guarantee a benign course, and unstable patients need urgent care regardless of the number. This calculator is an educational reference, not medical advice.
This is a reference tool, not a diagnosis or medical advice. Results depend on the laboratory, assay and clinical context, and reference intervals vary between labs and by age and sex — always read your result against the range printed on your own report and discuss it with a qualified healthcare professional.
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