Horner's syndrome

This code represents Horner's syndrome, a rare neurological disorder characterized by a classic triad of symptoms: miosis (constricted pupil), ptosis (drooping eyelid), and anhidrosis (decreased sweating) on one side of the face. It results from damage to the sympathetic nerve pathway that supplies the eye and face.

Assign this code when documentation explicitly states a diagnosis of Horner's syndrome. This typically occurs following a neurological examination confirming the characteristic signs, often after trauma, tumor, or other lesions affecting the sympathetic chain.

• Always look for laterality (right, left, or bilateral) in the documentation; if not specified, query the provider.
• Code any underlying cause or associated condition (e.g., tumor, stroke, trauma) as a primary or secondary diagnosis.
• Do not confuse with other causes of ptosis or miosis; ensure the full syndrome is documented.