What causes postural hypotension?

When you stand, blood naturally shifts towards your legs. Nerves, blood vessels and the heart usually respond by tightening vessels and adjusting the pulse. Postural hypotension occurs when that response is delayed or insufficient. Dehydration, vomiting, fever, prolonged bed rest and blood loss can reduce circulating fluid. Medicines for blood pressure, the heart or mood can sometimes contribute. Diabetes, Parkinson’s disease and other conditions affecting automatic nerve control may also play a part. Light-headedness, blurred vision, weakness or fainting can occur, especially after getting up quickly.

Rise in stages: sit on the edge of the bed, move your ankles, then stand while holding a stable surface. Drink fluids if a clinician has not restricted them, and avoid standing still for long periods. Do not stop a prescribed medicine on your own; a GP can review timing, doses and other causes. Keep a record of when symptoms occur, what you were doing, and whether you had eaten or drunk recently. A GP may check blood pressure lying and standing, review medicines, and arrange blood tests or other assessment when indicated.

Arrange medical advice if dizziness keeps returning, follows a medicine change, or affects walking and daily activities. Seek urgent help after fainting with an injury, chest pain, severe breathlessness, a new irregular heartbeat, marked weakness, confusion, or signs of significant bleeding. Call emergency services if someone cannot be woken, has trouble speaking or moving, or remains seriously unwell. Until assessed, sit or lie down as soon as symptoms begin and avoid driving or climbing while light-headed.

Could any of my medicines or health conditions be lowering my blood pressure? Should I change how I rise, exercise or drink fluids? Do I need lying and standing blood pressure checks, blood tests or a heart assessment?