What is the workup for orthostatic (postural) hypotension?

Workup for Orthostatic Dizziness

The workup for orthostatic dizziness centers on proper orthostatic vital sign measurement using a standardized protocol, followed by targeted laboratory testing and ECG to identify reversible causes and underlying autonomic dysfunction. 1, 2

Initial Orthostatic Vital Sign Measurement

Patient Preparation

• Fast the patient for 3 hours before testing 1, 2
• Avoid nicotine, caffeine, theine, or taurine-containing drinks on the day of examination 1, 2
• Conduct testing in a temperature-controlled environment (21-23°C) 1, 2
• Use a validated, calibrated blood pressure device with appropriate cuff size based on arm circumference 1, 3

Measurement Protocol

• Have the patient rest in supine position (preferred for greater sensitivity) for 5 minutes before baseline measurement 3
• Measure BP in both arms at the first visit; if systolic BP differs by >10 mmHg between arms, use the arm with higher BP for all subsequent measurements 1, 3
• Record baseline blood pressure and heart rate 3, 2
• Measure BP and heart rate at 1 minute and 3 minutes after standing, maintaining the arm at heart level during all measurements 1, 3, 2
• Record heart rate and check for arrhythmias during assessment 3

Critical timing note: While guidelines recommend 3-minute measurements, research shows that measurements within the first minute (particularly at 28 seconds) are most strongly associated with dizziness symptoms and adverse outcomes including falls, fractures, syncope, and mortality 4. Consider extending standing time beyond 3 minutes if symptoms suggest orthostatic hypotension but initial testing is negative (to detect delayed orthostatic hypotension) 1.

Diagnostic Criteria

• Classical orthostatic hypotension: Sustained decrease in systolic BP ≥20 mmHg OR diastolic BP ≥10 mmHg OR systolic BP falling to <90 mmHg within 3 minutes of standing 1, 3, 2
• Initial orthostatic hypotension: BP decrease >40 mmHg systolic and/or >20 mmHg diastolic within 15 seconds of standing 1, 2
• Delayed orthostatic hypotension: BP drop meeting criteria but occurring beyond 3 minutes of standing 1, 2
• In patients with supine hypertension, use a threshold of ≥30 mmHg systolic drop 1, 2

Heart Rate Response Assessment

• Measure heart rate changes to assess baroreflex integrity 5
• Neurogenic orthostatic hypotension shows blunted HR increase (usually <10 beats per minute) because autonomic HR control is impaired 1
• Normal response to standing is a slight BP reduction (4 mmHg systolic, 5 mmHg diastolic) and an increase in heart rate 3

Targeted History and Physical Examination

Symptom Assessment

• Dizziness, lightheadedness, visual disturbances (blurred vision), weakness, and fatigue 2, 6
• Syncope, presyncope, palpitations, dyspnea, and chest pain 2, 6
• Less common: neck and shoulder pain 6
• Important distinction: Patients with positional dizziness (dizziness with head movements) have BPPV in 37% of cases, while those with simple orthostatic dizziness (without positional component) have orthostatic intolerance in 38.5% of cases 7

Medication Review

• Diuretics, vasodilators, alpha-blockers, antihypertensives 2, 5
• Tricyclic antidepressants, phenothiazines 2
• Alcohol 2

Comorbidity Assessment

• Diabetes mellitus (autonomic neuropathy) 2, 8
• Parkinson's disease, multiple system atrophy, pure autonomic failure (primary autonomic failure) 1, 2
• Amyloidosis, autoimmune disorders (secondary autonomic neuropathies) 2
• Cardiovascular disease, endocrine disorders 2

Laboratory Testing

Obtain the following baseline laboratory tests to identify reversible causes: 2

• Complete blood count to rule out anemia 2
• Serum electrolytes to assess for electrolyte disturbances 2
• Serum creatinine with eGFR to evaluate renal function 2
• Fasting blood glucose to screen for diabetes 2
• Thyroid-stimulating hormone (TSH) to rule out thyroid dysfunction 2

Cardiac Evaluation

12-Lead ECG

• Perform ECG to rule out arrhythmias, conduction abnormalities, and structural heart disease 1, 2
• Caveat: Blood pressure cannot be measured reliably in patients with atrial fibrillation using standard instruments 3

Additional Cardiac Testing (When Indicated)

• Echocardiography may be used if cardiac cause is suspected, though diagnostic yield is low without clinical evidence of cardiac disease 1
• 24-hour ambulatory blood pressure monitoring can detect patterns of BP variability and identify supine hypertension (common in neurogenic orthostatic hypotension) 1

Advanced Testing Considerations

Head-Up Tilt Table Testing

• Use when standard orthostatic vital signs are nondiagnostic but clinical suspicion remains high 6
• Can aid in assessing treatment response in patients with autonomic disorders 6
• Continuous BP measurement devices are preferred over interval devices for accurate diagnosis, as interval devices have low concordance with continuous measurements 1

Positional Testing for BPPV

• Consider positional tests for BPPV as an essential diagnostic test for patients with orthostatic dizziness, even when dizziness is not clearly associated with positional changes 7

Common Pitfalls to Avoid

• Don't use seated baseline measurements exclusively: Supine position is preferred for greater sensitivity, though sitting is more practical in clinical settings 3
• Don't stop at 3 minutes if symptoms persist: Extend standing time to detect delayed orthostatic hypotension 1
• Don't overlook early measurements: Measurements within the first minute are most strongly associated with symptoms and adverse outcomes 4
• Don't assume pseudohypertension: In elderly patients with calcified arteries, pseudohypertension may lead to overtreatment and iatrogenic orthostatic hypotension 1
• Don't focus solely on BP drop magnitude: Symptoms depend more on the absolute BP level than the magnitude of the fall 1