Orthostatic Hypotension Workup and Management
Initial Diagnostic Evaluation
Measure blood pressure after 5 minutes of lying or sitting, then at 1 and/or 3 minutes after standing. Orthostatic hypotension is defined as a sustained drop of ≥20 mmHg systolic or ≥10 mmHg diastolic blood pressure within 3 minutes of standing 1. In patients with baseline supine hypertension, use a threshold of ≥30 mmHg systolic drop 1.
Key History Elements to Obtain
Symptom characterization: Ask specifically about lightheadedness, dizziness, visual disturbances (blurred vision, tunnel vision), weakness, fatigue, palpitations, headache, neck/shoulder pain ("coat hanger syndrome"), dyspnea, chest pain, and syncope or near-syncope 1, 2.
Timing and triggers: Document when symptoms occur (immediately upon standing vs. delayed), duration of standing before symptoms develop, and any precipitating factors such as meals, warm environments, or exertion 3, 4.
Medication review: Identify all blood pressure-lowering medications, diuretics, alpha-blockers (including prostate medications), sedatives, antidepressants, and over-the-counter cold remedies or diet aids that may contain sympathomimetics 1, 5, 6.
Associated conditions: Screen for diabetes mellitus, Parkinson's disease, other neurodegenerative disorders, cardiovascular disease, and autonomic dysfunction 6, 2, 7.
Family history: Document sudden cardiac death, syncope, arrhythmias, or structural heart disease in first-degree relatives 3.
Physical Examination Priorities
Orthostatic vital signs: Measure blood pressure and heart rate supine (after 5 minutes rest), then at 1 minute and 3 minutes after standing 1. A heart rate increase <15 bpm suggests neurogenic orthostatic hypotension 2, 4.
Cardiovascular examination: Assess heart sounds, rhythm, peripheral pulses, and signs of volume depletion 3.
Neurological assessment: Evaluate for signs of autonomic dysfunction or neurodegenerative disease 6, 7.
Essential Testing
12-lead ECG: Obtain in all patients to detect arrhythmias, conduction abnormalities, channelopathies, or structural heart disease 1, 3.
Laboratory studies: Order only if clinically indicated based on history and examination—consider complete blood count (anemia), electrolytes, glucose (hypoglycemia), and renal function 3, 6.
Head-up tilt table testing: Reserve for patients with high clinical suspicion but negative bedside orthostatic measurements, those unable to stand safely, or when assessing treatment response in autonomic disorders 6, 2, 8.
Classification and Risk Stratification
Distinguish between neurogenic and non-neurogenic orthostatic hypotension based on heart rate response. Neurogenic orthostatic hypotension shows inadequate heart rate increase (<15 bpm) and indicates autonomic nervous system dysfunction, often associated with Parkinson's disease, multiple system atrophy, or pure autonomic failure 1, 2, 4, 7. Non-neurogenic causes include medications, dehydration, blood loss, and cardiac dysfunction 1.
Orthostatic Hypotension Subtypes
Initial (immediate) orthostatic hypotension: Transient blood pressure drop within 15 seconds of standing with rapid recovery 1.
Classic orthostatic hypotension: Sustained blood pressure drop within 3 minutes of standing 1.
Delayed orthostatic hypotension: Blood pressure drop occurring >3 minutes after standing, often gradual 1, 4.
Management Algorithm
Step 1: Address Reversible Causes
Review and discontinue or reduce medications that worsen orthostatic hypotension. Prioritize stopping or switching alpha-blockers, sedatives, prostate-specific medications, and unnecessary blood pressure-lowering drugs rather than simply reducing overall antihypertensive therapy 1, 6, 2.
- Correct dehydration, blood loss, or electrolyte abnormalities 6.
- Treat underlying conditions such as anemia or endocrine disorders 6.
Step 2: Non-Pharmacological Interventions (First-Line for All Patients)
Increase water intake to 2-2.5 liters daily and salt intake to 6-10 grams daily to expand intravascular volume 6, 8.
Implement physical counterpressure maneuvers: Teach leg crossing, squatting, and arm tensing to acutely raise blood pressure when symptoms occur 3, 8.
Use compression garments: Apply elastic abdominal binders and compression stockings (waist-high, 30-40 mmHg) to reduce venous pooling 6, 8.
Modify sleeping position: Elevate the head of the bed 10-20 degrees to reduce supine hypertension and improve morning orthostatic tolerance 5, 6.
Avoid exacerbating factors: Limit prolonged standing, hot environments, large meals, and alcohol consumption 2, 4.
Step 3: Pharmacological Treatment (When Non-Pharmacological Measures Insufficient)
Initiate midodrine as first-line pharmacotherapy for symptomatic orthostatic hypotension. Midodrine is FDA-approved and increases standing systolic blood pressure by 15-30 mmHg at 1 hour after a 10 mg dose 5. Start with 2.5-5 mg three times daily, with the last dose at least 3-4 hours before bedtime to minimize supine hypertension 5. Maximum dose is 10 mg three times daily 5.
Consider droxidopa as an alternative first-line agent, particularly in neurogenic orthostatic hypotension 2, 7.
Use fludrocortisone (0.1-0.2 mg daily) as a second-line option for volume expansion, though it has concerning long-term effects including supine hypertension and hypokalemia 6, 2, 8.
Pyridostigmine (30-60 mg three times daily) may be added as adjunctive therapy, particularly in neurogenic orthostatic hypotension 6.
Critical Monitoring Considerations
Monitor for supine hypertension, which commonly coexists with neurogenic orthostatic hypotension and requires careful management 5, 4, 7. Instruct patients to avoid lying flat and to take the last midodrine dose 3-4 hours before bedtime 5.
Assess renal and hepatic function before initiating midodrine and periodically thereafter, as desglymidodrine is renally eliminated 5.
Avoid combining midodrine with other vasoconstrictors (phenylephrine, pseudoephedrine, ephedrine) due to additive hypertensive effects 5.
Continue pharmacotherapy only if patients report significant symptomatic improvement in their ability to perform activities of daily living 5.
Common Pitfalls to Avoid
- Do not measure orthostatic vitals only at 3 minutes—initial orthostatic hypotension occurs within 15 seconds and may be missed 1.
- Do not assume normal bedside orthostatic measurements exclude the diagnosis in patients with high clinical suspicion; proceed to tilt table testing 6, 2.
- Do not simply reduce all antihypertensive medications—selectively switch agents that worsen orthostatic hypotension rather than undertreating hypertension 1.
- Do not overlook supine hypertension monitoring when treating orthostatic hypotension, particularly in neurogenic cases 5, 4, 7.