Nontraumatic subarachnoid hemorrhage from unsp intracran art

This code signifies a spontaneous bleeding into the subarachnoid space, originating from an intracranial artery, where the specific artery involved is not documented. This condition is a serious type of stroke, often presenting with a sudden, severe headache.

Apply this code when documentation confirms a nontraumatic subarachnoid hemorrhage and the physician's notes explicitly state or imply that the source artery is unknown or unspecified. This is appropriate when diagnostic imaging (e.g., CT angiography) has not identified the specific ruptured vessel.

• Do not use this code if the documentation specifies a ruptured aneurysm (e.g., saccular, fusiform) or other specific arterial malformation.
• Ensure the documentation clearly indicates a nontraumatic origin; otherwise, consider codes for traumatic subarachnoid hemorrhage.
• Always sequence this code as the primary diagnosis when it is the reason for the encounter.