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Horner's syndrome
System: Neurological Signs · All neurological signs
What it is — and how it is elicited
Drooping of the upper eyelid (ptosis), a small pupil (miosis) and loss of sweating on one side of the face, sometimes with the eye appearing sunken.
What a positive finding suggests
Associated with disruption of the sympathetic nerve pathway to the eye, anywhere from the brainstem through the neck and upper chest.
◈ Behind the name
Johann Friedrich Horner (1831–1886), Swiss ophthalmologist.
Related signs — Neurological Signs
Browse the H section of the A–Z list or return to the Clinical Signs hub.
Please note: This page is an educational reference about clinical examination signs. A clinical sign supports — and never replaces — a full clinical evaluation, examination and appropriate testing. A sign being present does not by itself prove a diagnosis, and an absent sign does not rule one out. If you have symptoms that worry you, see a health professional.