Sudden idiopathic hearing loss, unspecified ear

This code represents an acute, unexplained sensorineural hearing loss that occurs rapidly, typically within 72 hours. It is characterized by a sudden decrease in hearing ability without an identifiable cause, affecting one or both ears. The "idiopathic" nature signifies that the underlying etiology remains unknown after thorough investigation.

Use this code for patients presenting with sudden onset hearing loss where diagnostic workup has failed to identify a specific cause such as trauma, infection, or ototoxic drug exposure. Documentation should clearly state "sudden idiopathic hearing loss" and indicate that the affected ear is unspecified or not yet determined.

• Do not use this code if a specific cause for the sudden hearing loss has been identified (e.g., viral labyrinthitis, acoustic neuroma).
• If the affected ear is known, use the more specific codes H91.21 (right ear) or H91.22 (left ear).
• Ensure documentation supports the "sudden" and "idiopathic" aspects of the diagnosis.