The Glasgow-Blatchford bleeding score (GBS) is a screening tool to assess the likelihood that a patient with an acute upper gastrointestinal bleeding (UGIB) will need to have medical intervention such as a blood transfusion or endoscopic intervention. The tool may be able to identify patients who do not need to be admitted to hospital after a UGIB. Advantages of the GBS over the Rockall score, which assesses the risk of mortality in patients with UGIB, include a lack of subjective variables such as the severity of systemic diseases and the lack of a need for oesophagogastroduodenoscopy (OGD) to complete the score, a feature unique to the GBS.
In a controlled study, 16% of patients presenting with UGIB had a GBS score of "0", considered low. Among these patients there were no deaths or interventions needed and the patients were able to be effectively treated in an outpatient setting. 
The score is calculated using the table below:
|Admission risk marker||Score component value|
|Blood Urea (mmol/L)|
|Haemoglobin (g/L) for men|
|Haemoglobin (g/L) for women|
|Systolic blood pressure (mm Hg)|
|Pulse ≥100 (per min)||1|
|Presentation with melaena||1|
|Presentation with syncope||2|
In the validation group, scores of 6 or more were associated with a greater than 50% risk of needing an intervention.
Score is equal to "0" if the following are all present:
- Hemoglobin level >12.9 g/dL (men) or >11.9 g/dL (women)
- Systolic blood pressure >109 mm Hg
- Pulse <100/minute
- Blood urea nitrogen level <6.5 mg/dL
- No melena or syncope
- No past or present liver disease or heart failure
- "A risk score to predict need for treatment for uppergastrointestinal haemorrhage". Retrieved 2009-02-17.
- "Outpatient management of patients with low-risk upper-gastrointestinal haemorrhage: multicentre validation and prospective evaluation". Retrieved 2009-01-24.
-  Stanley AJ et al. Outpatient management of patients with low-risk upper-gastrointestinal haemorrhage: Multicentre validation and prospective evaluation. Lancet 2009 Jan 3; 373:42. Summary Retrieved from Journal Watch 1/20/09 from Journal Watch Gastroenterology January 9, 2009
- "Glasgow-Blatchford bleeding score". Retrieved 2009-01-24.