Dizziness Type Classifier

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name: dizziness-type-classifier
description: Classifies a patient's dizziness into one of four categories — vestibular/vertigo, presyncope, disequilibrium, or nonspecific — using history, timing, triggers, and associated symptoms. Use when a patient presents with dizziness, giddiness, lightheadedness, feeling off-balance, spinning, or nearly blacking out and you need to determine the type before further workup.
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# Dizziness Type Classifier

## Step 1 — Anchor to History, Not Symptom Quality

> Do NOT rely on whether the patient says "spinning" vs "lightheaded." Many patients describe their dizziness inconsistently, and symptom quality alone is unreliable. Instead, focus on **timing, triggers, and associated symptoms**.

Ask:
- When does it happen? (standing, lying down, head movement, out of the blue)
- How long does each episode last? (seconds, minutes, hours, constant)
- What makes it worse?
- What other symptoms come with it?

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## Step 2 — Is This Vestibular / Vertigo?

**Suspect vestibular if ALL of the following:**

| Feature | Vestibular pattern |
|---|---|
| Trigger | Head movement makes it worse (patient afraid to move) |
| Duration | Episodes last seconds to hours; NOT continuously present for months |
| Quality | Spinning, whirling, tilting — but vague descriptions do NOT exclude it |
| Exam | Nystagmus present (or Dix-Hallpike positive) |
| Associated | Nausea, postural instability |

> ⚠️ Constant dizziness lasting months is usually NOT vestibular — central adaptation corrects vestibular lesions within weeks.

**Triggers that point to vestibular:**
- Rolling over in bed, bending neck back, lying down → positional vertigo (BPPV)
- Head motion in any direction → vestibular disorder (all vestibular dizziness worsens with head movement)
- Coughing, sneezing, Valsalva → superior canal dehiscence or perilymphatic fistula

→ **If vestibular: proceed to Peripheral vs Central Vertigo Differentiator**

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## Step 3 — Is This Presyncope?

**Suspect presyncope if:**

| Feature | Presyncope pattern |
|---|---|
| Trigger | Upright posture (standing or seated); NOT lying down |
| Quality | "Nearly blacking out," feeling of impending faint, warmth, pallor, visual greyout |
| Duration | Seconds to minutes |
| Associated | Diaphoresis, nausea, palpitations, chest discomfort, dyspnoea |
| History | Cardiac disease, dehydration, antihypertensives, antidepressants |

> ⚠️ If dizziness occurs while lying down, think cardiac arrhythmia — not orthostatic hypotension.

**Subtypes to consider:**
- **Orthostatic hypotension** — occurs on standing; confirm with BP/pulse lying → standing (≥20 mmHg systolic drop)
- **Cardiac arrhythmia** — occurs lying or sitting; palpitations may be present
- **Vasovagal** — triggered by pain, emotion, prolonged standing

→ **If presyncope: evaluate as syncope (orthostatic vitals, ECG, cardiac history)**

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## Step 4 — Is This Disequilibrium?

**Suspect disequilibrium if:**

| Feature | Disequilibrium pattern |
|---|---|
| Context | Dizziness only when walking or standing; absent when lying down |
| Quality | Sense of imbalance, unsteadiness — NOT spinning, NOT near-faint |
| Exam | Gait disturbance, signs of neuropathy, parkinsonism, or cerebellar dysfunction |
| Associated | Falls, wide-based gait, leg weakness, sensory loss |

**Common causes:**
- Peripheral neuropathy
- Parkinson's disease / parkinsonism
- Cerebellar disease (also look for dysarthria, gaze-evoked nystagmus, limb dysmetria)
- Cervical spondylosis / cervical myelopathy
- Drug toxicity
- Visual impairment (worsens any balance disorder)

→ **If disequilibrium: neurologic examination + gait observation; targeted investigation for underlying cause**

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## Step 5 — Nonspecific Dizziness

**Consider if:** dizziness does not fit the above patterns cleanly — vague "I'm just dizzy," no reproducible trigger, often in young healthy patients without neurologic or cardiovascular disease.

**Common causes:**
- Anxiety, panic disorder, depression (primary cause in ~25% of nonspecific dizziness)
- Hyperventilation (confirm by asking patient to hyperventilate; if dizziness reproduced AND no nystagmus appears, likely psychogenic)
- Medication side effects — especially antidepressants, anticonvulsants, anticholinergics, antihypertensives
- Hypoglycaemia or other metabolic disorders
- Post-head trauma / whiplash (provoked by visual stimuli — malls, scrolling screens, patterned environments)
- Milder forms of vestibular or presyncope not meeting full criteria

> ⚠️ If hyperventilation reproduces dizziness AND nystagmus appears: this is a vestibular lesion unmasked by hyperventilation — NOT psychogenic.

→ **If nonspecific: medication review, metabolic screen, consider psychiatry assessment if anxiety/depression features present**

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## Clinical Guardrails

- **Don't over-rely on the word "spinning"** — cardiac patients with presyncope can describe a spinning sensation; vestibular patients may never say spinning.
- **"Constant for months" ≠ vestibular** — the CNS compensates for vestibular lesions. Months of constant dizziness is almost always psychogenic, metabolic, or multifactorial.
- **Older patients are multifactorial** — up to 44% of dizzy patients ≥65 have more than one cause. Screen for: anxiety, depression, impaired balance, past MI, postural hypotension, polypharmacy (≥5 drugs), hearing impairment.
- **Always check medications** — antihypertensives, antidepressants, anticonvulsants, and anticholinergics are common contributors and are often remediable.

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*Source: Barton JS. "Approach to the patient with dizziness." UpToDate. Last updated Dec 11, 2025.*