What is the appropriate diagnostic workup and treatment for a patient experiencing occasional dizziness, nausea, fatigue, and lightheadedness, with potential underlying conditions such as anemia, infection, electrolyte imbalance, hypothyroidism, cardiac arrhythmias, or neurological disorders?

Diagnostic Workup for Occasional Dizziness, Nausea, Fatigue, and Lightheadedness

Begin with a focused history emphasizing timing and triggers rather than the patient's subjective description of "dizziness," followed by targeted physical examination including orthostatic vital signs, Dix-Hallpike maneuver, and neurologic assessment—laboratory testing should focus on complete blood count, comprehensive metabolic panel, thyroid function, and ECG, while imaging is reserved only for patients with red flag features. 1, 2

Initial History: Critical Details to Elicit

Focus on these specific diagnostic elements rather than vague symptom descriptions:

• Timing pattern: Determine if symptoms are brief episodic (seconds to minutes), acute persistent (days to weeks), spontaneous episodic (minutes to hours), or chronic (weeks to months) 1, 3
• Triggers: Identify if symptoms occur with positional changes, standing up, specific head movements, or spontaneously without provocation 1, 2
• Associated symptoms: Ask specifically about hearing loss, tinnitus, aural fullness (suggesting Ménière's disease), headache with photophobia/phonophobia (suggesting vestibular migraine), or chest pain/palpitations (suggesting cardiac etiology) 1, 4
• Medication review: This is a leading reversible cause—specifically review antihypertensives, sedatives, anticonvulsants, and psychotropic drugs 1
• Vascular risk factors: Document age >50, hypertension, diabetes, atrial fibrillation, prior stroke 1

Physical Examination Protocol

Essential Bedside Tests

• Orthostatic vital signs: Measure blood pressure and heart rate supine, then at 1 and 3 minutes after standing—classical orthostatic hypotension is defined as ≥20 mmHg systolic or ≥10 mmHg diastolic drop within 3 minutes 4
• Dix-Hallpike maneuver: Perform bilaterally for any patient with positional symptoms—positive findings include torsional upbeating nystagmus with 5-20 second latency that resolves within 60 seconds, confirming BPPV 4, 1
• Neurologic examination: Assess for focal deficits, gait ataxia, dysmetria, cranial nerve abnormalities, and limb weakness 4, 1
• Nystagmus assessment: Observe for spontaneous nystagmus at rest and with gaze—purely vertical nystagmus without torsional component or direction-changing nystagmus suggests central pathology 5

Red Flags Requiring Urgent Evaluation

Any of these features demand immediate neuroimaging (MRI brain with diffusion-weighted imaging) and neurologic consultation:

• Severe postural instability with falling 5
• New severe headache accompanying dizziness 1
• Focal neurologic deficits on examination 1
• Sudden unilateral hearing loss 1
• Downbeating nystagmus or purely vertical nystagmus without torsional component 5
• Failure to respond to appropriate peripheral vertigo treatments 5

Laboratory Testing Strategy

Initial Laboratory Panel

Order these tests for all patients with unexplained dizziness, nausea, fatigue, and lightheadedness:

• Complete blood count: To evaluate for anemia, which commonly causes fatigue and lightheadedness 6, 2
• Comprehensive metabolic panel: To assess for electrolyte imbalances (sodium, potassium, calcium, magnesium), renal dysfunction, and glucose abnormalities 6, 2
• Thyroid-stimulating hormone (TSH): Hypothyroidism frequently presents with fatigue, and both hypothyroidism and hyperthyroidism can cause dizziness 4, 6
• Electrocardiogram: To screen for arrhythmias (bradycardia, tachycardia, atrial fibrillation) that can cause presyncope and dizziness 4, 2

Additional Testing Based on Clinical Context

• Audiometry: Obtain for patients with unilateral tinnitus, hearing loss, or suspected Ménière's disease 1
• Coagulation studies: Consider if cerebral venous thrombosis is suspected based on severe headache with neurologic symptoms 4

Imaging Decisions

When Imaging Is NOT Indicated

• Brief episodic vertigo with typical BPPV features and positive Dix-Hallpike test 1
• Acute persistent vertigo with normal neurologic exam and peripheral features on examination 1
• Nonspecific dizziness without vertigo, ataxia, or neurologic deficits 1

When Imaging IS Indicated

MRI brain without contrast is the preferred modality for:

• Abnormal neurologic examination 1
• High vascular risk patients (age >50, hypertension, diabetes, prior stroke) with acute vestibular syndrome—11-25% may have posterior circulation stroke despite normal neurologic exam 1
• Unilateral or pulsatile tinnitus 1
• Asymmetric hearing loss 1
• Progressive neurologic symptoms 1

CT head has extremely low diagnostic yield (<1%) for isolated dizziness and misses most posterior circulation infarcts—avoid using CT as the primary imaging modality unless MRI is unavailable. 1

Common Diagnostic Pitfalls to Avoid

• Relying on patient's description of "spinning" versus "lightheadedness": This distinction is unreliable—focus instead on timing and triggers 1
• Assuming normal neurologic exam excludes stroke: 75-80% of patients with acute vestibular syndrome from posterior circulation infarct have no focal neurologic deficits 1
• Ordering routine imaging for isolated dizziness: This has very low yield and most findings are incidental 1
• Missing medication-induced dizziness: This is one of the most common and reversible causes—always review the medication list 1
• Overlooking psychiatric causes: Anxiety, panic disorder, and depression are common causes of chronic dizziness and should be screened 1

Management Based on Etiology

If BPPV is Confirmed (Positive Dix-Hallpike)

• Perform canalith repositioning procedure (Epley maneuver) immediately—80% success after 1-3 treatments, 90-98% with repeat maneuvers 1
• Do not prescribe vestibular suppressants as they prevent central compensation 5
• No imaging or additional testing needed for typical cases 1

If Orthostatic Hypotension is Identified

• Review and adjust medications causing hypotension 4
• Recommend increased fluid and salt intake, compression stockings, and gradual position changes 4
• Consider alpha agonists or mineralocorticoids for refractory cases 6

If Laboratory Abnormalities are Found

• Anemia: Investigate cause and treat appropriately with iron supplementation, vitamin B12, or folate as indicated 6
• Electrolyte imbalances: Correct underlying abnormalities 6
• Hypothyroidism: Initiate levothyroxine replacement 4
• Cardiac arrhythmias: Refer to cardiology for management 4

If No Clear Etiology is Identified

• Consider vestibular rehabilitation therapy for persistent symptoms—this significantly improves gait stability and is particularly beneficial for elderly patients 1
• Screen for psychiatric disorders (anxiety, depression) and treat accordingly 1
• Reassess within one month to document resolution or persistence of symptoms 1