Orthostatic hypotension (OH) is a condition characterized by a sustained decrease in systolic blood pressure of ≥15–20 mmHg or diastolic pressure of ≥10 mmHg when a patient moves from a supine to sitting or standing position, with or without a compensatory increase in heart rate ≥20 bpm. It is commonly associated with light-headedness, syncope, blurred vision, or weakness. OH reflects impaired compensatory vasomotor responses and may occur in hypotensive, normotensive, or hypertensive patients.

Pathophysiology

Normal postural changes activate the autonomic nervous system to maintain adequate cerebral perfusion. Upon standing:

1. Gravitational shift causes ~500–1000 mL of blood to pool in lower extremities and splanchnic circulation.

2. Baroreceptor response: Stretch receptors in the carotid sinus and aortic arch sense decreased arterial pressure → activate sympathetic nervous system.

3. Compensatory mechanisms:

   • ↑ Heart rate (chronotropy)

   • ↑ Cardiac contractility (inotropy)

   • Peripheral vasoconstriction → maintains BP and cerebral perfusion

OH occurs when these compensatory mechanisms fail due to:

• Autonomic dysfunction (neurogenic OH)

• Hypovolemia (hemorrhage, dehydration)

• Drug effects (antihypertensives, diuretics)

• Endocrine disorders (adrenal insufficiency, diabetes, hypothyroidism)

• Age-related decline in baroreceptor sensitivity

History and Physical Examination

History:

• Episodes of dizziness, syncope, blurred vision upon standing

• Fatigue, orthopnea, impotence, nausea, headache, abdominal/chest discomfort, GI bleeding

• Medication history, including antihypertensives, diuretics, psychotropics

Physical Examination:

• Vital signs in supine, sitting, and standing positions (measure BP 5 min after position change)

• Skin turgor, pallor, diaphoresis

• Peripheral pulses

• Heart and lung auscultation

• Muscle strength, gait assessment

Emergency Assessment:

• If tachycardia, altered LOC, or clammy skin present → suspect hypovolemic shock

• Immediate interventions: IV access, fluids/blood replacement, monitor intake/output and vitals every 15 min

Medical causes of orthostatic hypotension

Special considerations

• Fluid balance: Monitor intake/output and daily weight

• Positioning: Elevate head of bed; assist gradual transition from supine → sitting → standing; return to bed if dizziness occurs

• Safety: Always supervise patient during ambulation; assess need for assistive devices (cane/walker)

• Diagnostics: CBC, electrolytes, drug levels, urinalysis, 12-lead ECG, chest X-ray

Patient counseling

• Avoid rapid posture changes

• Maintain adequate hydration

• Report recurrent dizziness, fainting, or other associated symptoms

• Use assistive devices if needed

Pediatric pointers

• Recognize age-specific normal BP:

  • Birth–3 mo: systolic 40–80 mmHg

  • 3 mo–1 yr: systolic 80–100 mmHg

  • 1–12 yrs: systolic = 100 + 2 × (age − 1) mmHg

• OH causes in children often mirror adults: dehydration, autonomic dysfunction, medications

Geriatric pointers

• Common due to autonomic dysfunction

• Postprandial hypotension occurs 45–60 min after meals; affects up to 1/3 of nursing home residents

References

1. Berkowitz CD. Berkowitz’s Pediatrics: A Primary Care Approach. 4th ed. USA: American Academy of Pediatrics; 2012.

2. Buttaro TM, Tybulski J, Bailey PP, Sandberg-Cook J. Primary Care: A Collaborative Practice. St. Louis, MO: Mosby Elsevier; 2008. p. 444–447.

3. Colyar MR. Well-Child Assessment for Primary Care Providers. Philadelphia, PA: F.A. Davis; 2003.

4. Sommers MS, Brunner LS. Pocket Diseases. Philadelphia, PA: F.A. Davis; 2012.

5. Freeman R. Clinical practice. Neurogenic orthostatic hypotension. N Engl J Med. 2008;358:615–624.

6. Low PA. Disorders of the autonomic nervous system. In: Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020. p. 2150–2158.

7. Kaufmann H, Biaggioni I. Autonomic failure: A textbook of clinical disorders of the autonomic nervous system. 5th ed. New York: Oxford University Press; 2017.