What should you know about causes of postural hypertension?

Standing shifts blood toward the legs. The body normally tightens blood vessels and adjusts the heart rate to maintain circulation to the brain. If that response is delayed or too strong, readings may change and you may feel light-headed, weak or unsteady. Dehydration, illness and medicines for blood pressure or heart problems can contribute.

Kidney disease, obesity, heart failure and obstructive sleep apnoea can affect blood-pressure regulation, while a history of stroke or transient ischaemic attack may change how symptoms are interpreted. Angina is a different condition, but chest discomfort during a posture-related episode still deserves prompt attention. A single home reading cannot establish the cause.

Move slowly from lying to sitting, pause before standing, and hold a stable surface if you feel unsteady. Keep a record of readings, posture, timing, symptoms, meals, fluid intake and medicines. Do not alter treatment or deliberately increase salt or fluids without clinical advice, particularly if you have heart or kidney problems. A clinician may compare readings after different positions and review your medicines.

Get urgent help for fainting, chest pain, severe breathlessness, new weakness on one side, trouble speaking, sudden confusion or a severe headache. Sit or lie down safely while help is arranged. Arrange a routine review for repeated dizziness, falls, blurred vision or readings that remain unusual, because the pattern and medication list help guide the evaluation.

Ask which posture-related readings matter, whether any medicine may be contributing, how to measure safely at home, and whether heart, kidney or neurological checks are appropriate.