What is the Hunt and Hess Scale?

The Hunt and Hess Scale is a five-grade clinical classification system for subarachnoid hemorrhage (SAH) introduced in 1968. It grades patients from Grade I (asymptomatic or mild headache) to Grade V (deep coma, decerebrate posturing), correlating with prognosis and surgical mortality.

How does the Hunt and Hess score differ from WFNS?

The World Federation of Neurosurgical Societies (WFNS) scale uses the Glasgow Coma Scale (GCS) plus the presence of focal deficits, making it more objective. The Hunt and Hess scale relies on clinical descriptors and is more subjective but remains widely used in neurosurgical practice.

What are the surgical mortality rates by grade?

Approximate surgical mortality rates reported in literature are: Grade I ~0-5%, Grade II ~2-10%, Grade III ~10-15%, Grade IV ~60-70%, Grade V ~70-100%. These figures vary across studies and modern outcomes may differ with advances in microsurgery and endovascular treatment.

Is this tool a substitute for clinical judgment?

No. This calculator is for educational and reference purposes only. Clinical grading of SAH requires direct patient assessment by a qualified physician. Always apply clinical judgment, institutional protocols, and specialist consultation when managing patients with subarachnoid hemorrhage.

Hunt and Hess Score Calculator

Select clinical findings to calculate the Hunt and Hess grade for subarachnoid hemorrhage and estimate surgical mortality risk.

Select Clinical Presentation

Choose the single grade that best describes the patient's condition.

Grade I

Asymptomatic, or mild headache and slight nuchal rigidity.

Grade II

Moderate to severe headache, nuchal rigidity, no neurological deficit other than cranial nerve palsy.

Grade III

Drowsiness, confusion, or mild focal neurological deficit.

Grade IV

Stupor, moderate to severe hemiparesis, early decerebrate rigidity, or vegetative disturbance.

Grade V

Deep coma, decerebrate rigidity, moribund appearance.

Add +1 for serious systemic disease or severe vasospasm

Hypertension, diabetes, atherosclerosis, chronic pulmonary disease, or angiographic vasospasm.

Select a grade on the left
and click Calculate Grade.

Quick Reference Table

Grade	Description	Mortality
I	Asymptomatic / mild headache	0–5%
II	Moderate headache, no deficit	2–10%
III	Drowsy, mild focal deficit	10–15%
IV	Stupor, hemiparesis	60–70%
V	Deep coma, decerebrate	70–100%

Summary

The Hunt and Hess Scale is a widely used clinical grading system for subarachnoid hemorrhage (SAH) severity, originally described in 1968. It classifies patients into five grades based on presenting neurological findings including headache severity, meningismus, level of consciousness, and focal deficits. Higher grades correlate with greater brain injury, worse prognosis, and higher surgical mortality. The scale helps neurosurgeons decide timing and approach for aneurysm repair.

How it works

Review the patient's presenting neurological status immediately after SAH.
Select the single grade description that best matches the clinical picture.
If the patient has a serious systemic illness or severe vasospasm, add one grade.
Read the calculated grade, typical prognosis, and estimated surgical mortality.
Use the result alongside imaging (CT, angiography) to guide management decisions.

Use cases

Grading subarachnoid hemorrhage severity at initial clinical assessment.
Estimating surgical risk and timing of aneurysm repair.
Communicating prognosis clearly between neurosurgery team members.
Stratifying patients for clinical research and outcome studies.
Tracking neurological deterioration with serial assessments.
Teaching medical students and residents about SAH management principles.

Frequently Asked Questions

Last updated: 2026-06-04 · Reviewed by Nham Vu