Vertigo from infrasound, subsequent encounter

This code signifies a patient experiencing dizziness or a sensation of spinning due to exposure to very low-frequency sound waves (infrasound), specifically during a follow-up visit for this condition. The vertigo is a direct physiological response to the infrasound, rather than a pre-existing inner ear disorder.

Use this code for patients presenting for ongoing management or evaluation of vertigo that was previously diagnosed as being caused by infrasound exposure. This applies to situations where the patient is not in the initial acute phase of the injury but is still receiving care related to the infrasound-induced vertigo.

• Ensure documentation clearly links the vertigo to infrasound exposure and indicates a subsequent encounter.
• Do not use for initial encounters; a different seventh character would be appropriate for the initial presentation.
• Consider co-reporting with external cause codes (V, W, X, Y codes) if the source of the infrasound is known and documented.