Every clinician who treats dizziness will eventually encounter a patient whose presentation looks like a routine vestibular complaint but turns out to be something far more serious. The ability to confidently identify red flags — and to act decisively — separates a competent clinician from an excellent one.
The Fundamental Principle
Every dizziness assessment begins with one question: is this central, peripheral, or systemic? Red flag recognition is how you answer it.
The HINTS exam outperforms early MRI for distinguishing central from peripheral causes of acute vestibular syndrome. Every dizziness clinician should perform it fluently.
Category 1: Neurological Red Flags
- •Pure vertical (downbeat or upbeat) nystagmus in primary gaze — never normal
- •Direction-changing nystagmus in eccentric gaze — suggests cerebellar/brainstem pathology
- •Nystagmus that does not suppress with fixation — central
- •Pendular nystagmus — MS, brainstem pathology
The HINTS Exam
- •Head Impulse — normal HI with acute dizziness = central
- •Nystagmus direction — direction-changing = central
- •Test of Skew — vertical skew on cover test = central brainstem/cerebellar lesion
Neurological Signs With Dizziness
- •Diplopia, dysarthria, dysphagia, facial numbness — brainstem
- •Limb ataxia or dysmetria — cerebellar
- •Sudden severe headache (thunderclap) — subarachnoid haemorrhage until proven otherwise
- •Horner's syndrome — Wallenberg / PICA territory stroke
Category 2: Vascular Red Flags
Vertebral artery dissection can occur in patients under 45 with minimal or no trauma. Sudden occipital headache + neck pain + dizziness in a young active patient is dissection until proven otherwise. Emergency.
Category 3: Otological Red Flags
- •Progressive unilateral SNHL with vestibular symptoms — rule out vestibular schwannoma
- •Sudden SNHL > 30 dB across three frequencies in < 72 hours — emergency referral (steroid window)
- •Dizziness with otorrhoea, otalgia, or signs of infection — labyrinthine fistula
Category 4: Systemic Red Flags
- •Aminoglycosides, loop diuretics, cisplatin — ototoxicity and bilateral vestibular loss
- •Hypoglycaemia, anaemia, hypothyroidism — easily missed metabolic causes
- •Hyperventilation syndrome — carpopedal spasm, perioral tingling
Want to master this in practice?
The Dizziness Decoded series gives you a complete, hands-on framework for assessing and treating vestibular and dizziness conditions. Small groups of 12. Real practice. Real confidence.