The Hunt and Hess scale grades SAH :

1. Asymptomatic or minimal headache + slight neck stiffness
2. Moderate or severe headache with neck stiffness, but no neurological deficit other than cranial nerve palsy.
3. Drowsiness with confusion or mild focal neurology
4. Stupor with moderate to severe hemiparesis or mild decerebrate rigidity
5. Deeply comatose with severe decerebrate rigidity.

Severity and mortality increase with grade.