What should you know about really low blood pressure?

One low reading may reflect posture, recent exertion, dehydration, illness, or an inaccurate cuff position. Some people naturally have lower readings without symptoms. Repeated low readings with symptoms deserve a clinical review. Causes can include fluid loss, medicines, heart rhythm or pumping problems, hormone conditions, infection, or bleeding.

Notice when symptoms occur: after standing, after meals, during illness, or after a medicine change. A home log can include the reading, position, symptoms, fluid intake, and medicines, but it should support—not replace—an examination.

If you feel faint, sit or lie down promptly and raise your legs if comfortable. Rise slowly, hold onto a stable surface, and avoid driving while light-headed. Sip fluids if you can drink safely, unless a clinician has restricted your fluid intake. Do not stop prescribed medicine or deliberately increase salt without professional advice. Arrange a GP Consultation to review repeated readings and possible causes.

Call emergency services for fainting with ongoing confusion, chest pain, severe breathlessness, new weakness on one side, heavy bleeding, cold clammy skin, or collapse. Seek same-day care for repeated near-fainting, vomiting or diarrhoea with inability to keep fluids down, a significant medicine-related change, or worsening weakness. A new episode after injury also needs prompt assessment.

Ask whether your readings are reliable, which medicines or illnesses could contribute, whether blood tests or an ECG are appropriate, and how to manage standing-related symptoms. Bring your log and the names of all prescription, over-the-counter, and herbal products.