🚑 Injury Severity Score (ISS)
UseAnatomic injury burden in polytrauma and trauma registries. Physiology is not included.
StrataISS ≥16 or ≥25 is often used as a major-trauma threshold; follow local trauma-centre definitions.
LimitsCode from the AIS dictionary, not from memory. · Multiple injuries in one region: take the highest AIS only. · Add RTS/TRISS for physiology.
SourceBaker SP, O'Neill B, Haddon W Jr, Long WB. The injury severity score: a method for describing patie…
This-shift next steps
After scoring: open the scene pack, peer scores, and the matching pathway. Local reference — no HIS write.
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Methodology · worked example, guidelines & full notes
Sum of three squares, max 75.
When to use
Anatomic injury burden in polytrauma and trauma registries. Physiology is not included.
How it works
ISS = a² + b² + c² (three highest regional AIS) Any AIS 6 → ISS 75. Range 0–75.
Key points
- Sum of three squares, max 75.
- AIS 6 scores 75 immediately.
- Anatomic only — no vital signs.
References
- Baker SP, O'Neill B, Haddon W Jr, Long WB. The injury severity score: a method for describing patients with multiple injuries and evaluating emergency care. J Trauma 1974;14:187-196
Worked calculation
The values below come from this tool's own example placeholders and are computed server-side with the formula shown on this page, so the arithmetic can be checked quickly. It demonstrates how to substitute values only — it is not clinical advice and not a real case.
| Head/neck AIS | 3 serious |
|---|---|
| Face AIS | 3 serious |
| Chest AIS | 3 serious |
| Abdomen/pelvic contents AIS | 3 serious |
| Extremities/pelvic girdle AIS | 3 serious |
| External AIS | 3 serious |
→ISS27
- Calculation：Sum of squares 3²+3²+3²
- Band：Very severe (major trauma often ISS ≥16 or ≥25)
| Head/neck AIS | 0 none |
|---|---|
| Face AIS | 0 none |
| Chest AIS | 0 none |
| Abdomen/pelvic contents AIS | 0 none |
| Extremities/pelvic girdle AIS | 0 none |
| External AIS | 0 none |
→ISS0
- Calculation：Sum of squares 0²+0²+0²
- Band：Minor
Verification & sources · governance
FAQ
Frequently asked questions
- Does Injury Severity Score (ISS) upload patient data? Where is it calculated?
- Calculation runs locally in the browser; inputs and results are not uploaded. For licensed clinicians only; interpret with history, investigations and local protocols — not a diagnosis or prescription.
- How is Injury Severity Score (ISS) calculated in practice? Can you show a worked example?
- Inputs: Head/neck AIS 3 serious, Face AIS 3 serious, Chest AIS 3 serious, Abdomen/pelvic contents AIS 3 serious, Extremities/pelvic girdle AIS 3 serious, External AIS 3 serious → Result: ISS 27（Calculation: Sum of squares 3²+3²+3², Band: Very severe (major trauma often ISS ≥16 or ≥25)） Inputs: Head/neck AIS 0 none, Face AIS 0 none, Chest AIS 0 none, Abdomen/pelvic contents AIS 0 none, Extremities/pelvic girdle AIS 0 none, External AIS 0 none → Result: ISS 0（Calculation: Sum of squares 0²+0²+0², Band: Minor）