EmergencyEmergency Guide
Double vision: Red Flags & Emergency Signs
New onset double vision can indicate a posterior communicating artery aneurysm (third nerve palsy), brainstem stroke, or raised intracranial pressure — immediate imaging is essential.
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If you have this symptom right now
Call 999 (UK) / 112 (EU) / 911 (US) immediately if any emergency warning signs are present. Do not drive yourself. Do not wait to see if it improves.
🚨 Call 999 / 112 Immediately
- ⚠Double vision with severe headache — posterior communicating artery aneurysm compressing CN III
- ⚠Sudden double vision with unsteady gait and slurred speech — brainstem stroke
- ⚠Double vision with ptosis and dilated fixed pupil — CN III palsy (aneurysm until proven otherwise)
- ⚠Double vision in a patient with known cancer — leptomeningeal metastasis
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- •Double vision with jaw claudication in elderly — temporal arteritis (cranial nerve involvement)
- •New double vision in a patient with diabetes or hypertension (microvascular CN palsy — usually benign but requires exclusion of aneurysm)
High-Risk Combinations
When double vision occurs together with any of these symptoms, urgency increases significantly:
Conditions to Rule Out Urgently
Posterior Communicating Artery Aneurysmemergency
CT + CTA; neurosurgery; risk of rupture and SAH
Brainstem Strokeemergency
MRI DWI (CT often misses posterior fossa); NIHSS scoring
Giant Cell Arteritisurgent
CN VI/IV involved; ESR + immediate steroids
Condition Authority Pages
Differential diagnosis analyses:
When to Call Emergency Services
- →Double vision with severe headache
- →Double vision with drooping eyelid and large dilated pupil
- →Double vision with slurred speech or unsteady walking