Orthostatic hypotension explained

Gravity draws some blood toward the legs when you stand. Normally, blood vessels tighten and the heart adjusts quickly. With orthostatic hypotension, that response may not keep blood flow to the brain steady for a moment, producing light-headedness or an unsteady feeling. Some people notice visual dimming, weakness, nausea, or a fainting spell.

Possible contributors include dehydration, prolonged bed rest, illness, nervous-system problems, and medicines that affect blood pressure or fluid balance. The symptom pattern matters: note whether it follows standing and improves after sitting or lying down. A clinician can check blood pressure and pulse in different positions and look for contributing factors.

Change position slowly. Before standing, move your ankles and sit briefly; use a stable surface and stop if symptoms begin. Sit or lie down promptly if you feel faint. Keep fluids and meals consistent with your clinician’s advice, and avoid changing prescribed medicines without guidance. Reduce fall hazards at home and ask for help with stairs when unsteady.

A [GP Consultation](/treatments/consultations-and-assessment/gp-consultation/) can assess recurring episodes and review medicines or related illness. You can also read about [Dizziness](/symptoms/dizziness/).

Book an assessment if episodes recur, interfere with walking, or lead to a fall or faint. Seek urgent help for chest pain, severe breathlessness, new confusion, new weakness on one side, difficulty speaking, or a serious injury. Get prompt advice if vomiting, diarrhoea, or another illness makes it difficult to keep fluids down.

Ask whether your symptoms fit a postural blood pressure change, which causes should be checked, whether any medicine needs review, and how to stand and exercise safely.