AKT · Cardiovascular/Circulation & blood pressurelow yield

Postural (orthostatic) hypotension

Failure of compensatory vasoconstriction on standing → fall in BP and cerebral perfusion

Overview

A sustained fall in blood pressure on standing (≥20 mmHg systolic or ≥10 mmHg diastolic within 3 minutes), causing light-headedness, dizziness, blurred vision or syncope. Common in the elderly and a major cause of falls. Causes are volume depletion, drugs (antihypertensives, diuretics, alpha-blockers, antidepressants), and autonomic failure (diabetes, Parkinson's, neuropathy).

Recognise

Light-headedness, dizziness, blurred vision, weakness or syncope on standing or after meals; relieved by sitting/lying
Documented postural drop: ≥20 mmHg systolic or ≥10 mmHg diastolic within 3 minutes of standing
Clues to autonomic failure (diabetes, Parkinson's, multiple system atrophy) or culprit drugs

Red flags

Recurrent falls/injury in the elderly → address as a falls risk (cross-ref acute_care falls framework)
Autonomic failure with severe symptoms → specialist input

Differentials & how to tell them apart

Vasovagal syncopetrigger + prodrome, not strictly on standing, no sustained postural BP drop

Cardiac syncope/arrhythmiaexertional, abnormal ECG

Dehydration/haemorrhagevolume depletion with tachycardia — correct the cause

Investigations

Lying and standing BP (the diagnostic measurement); review the drug chart; bloods for anaemia, glucose, U&Es, (and adrenal/autonomic causes if indicated); ECG; assess for an underlying neurological/autonomic disorder.

Management

Conservative measures + review culprit drugs; fludrocortisone/midodrine if refractory

1Confirm with lying/standing BP and review the drug chart and volume status. Conservative measures (slow rising, fluids/salt, compression stockings) and reduce/stop culprit drugs.Gate: In an older patient this is a key reversible cause of falls — address within a falls assessment; persistent symptoms point to autonomic failure (diabetes, Parkinson's, MSA).
2If symptoms persist despite conservative measures and drug rationalisation → fludrocortisone or midodrine under specialist guidance, and investigate/treat autonomic failure.

Conservative: rise slowly, adequate fluid/salt, compression stockings, avoid large meals/alcohol — first-line; treat volume depletion

Review and reduce culprit drugs — antihypertensives, diuretics, alpha-blockers, nitrates, tricyclics — often the cause and the cure

Fludrocortisone or midodrine — if conservative measures and drug rationalisation fail (specialist, especially in autonomic failure)

Key points

Light-headedness on standing + a drop of ≥20 mmHg systolic (or ≥10 diastolic) within 3 minutes = orthostatic hypotension. The drug chart is usually the culprit AND the cure (antihypertensives, diuretics, alpha-blockers, tricyclics). A major reversible cause of falls in the elderly.

Monitor & prognosis

Repeat lying/standing BP, falls/symptoms, response to drug changes.

Often improves with drug rationalisation/hydration; autonomic causes are chronic.

Source: NICE CKS; falls guidance (cross-ref acute_care)