What should you know about orthostatic hypotension?

When you stand, gravity briefly draws blood towards your legs. The nervous system normally responds by tightening blood vessels and adjusting the heart rate so the brain continues to receive blood. With orthostatic hypotension, that adjustment is too slow or insufficient, so symptoms may appear within moments of standing.

Possible contributors include dehydration, vomiting or diarrhoea, prolonged bed rest, heat, alcohol, some medicines and conditions affecting the heart, nerves or hormone balance. Symptoms can be occasional or recurrent. A clinician may compare blood pressure and pulse while you are lying down and after standing, then review medicines and other possible causes.

Dizziness is one possible symptom; learn more about [dizziness](/symptoms/dizziness/) and its broader causes. Repeated episodes, falls or fainting deserve a medical assessment even if you feel better afterwards.

If symptoms start, sit or lie down promptly and raise your legs if comfortable. Move from lying to sitting, pause, then stand slowly while holding a stable support. Keep fluids up unless a clinician has told you to restrict them, and take extra care in hot environments. Do not stop prescribed medicines or increase salt without medical advice; either change can be unsafe for some people.

Note when episodes happen, what you were doing, whether you had eaten or drunk recently, and any palpitations, chest discomfort or fainting. This record can help a clinician identify triggers and decide whether further checks are needed.

Arrange a GP appointment if symptoms keep returning, interfere with walking or daily activities, follow a medicine change, or lead to a fall or faint. A [GP consultation](/treatments/consultations-and-assessment/gp-consultation/) can help review the pattern and possible causes.

Seek urgent help for fainting with chest pain, severe breathlessness, a sustained fast or irregular heartbeat, new confusion, weakness on one side, trouble speaking, a serious injury, or symptoms that do not settle after lying down. Get prompt care if you cannot keep fluids down or appear severely dehydrated.

Ask whether any of your medicines, recent illness or health conditions could be contributing; whether you should check blood pressure at home; which fluid or activity advice fits your health; and what symptoms should prompt urgent care.