Heart failure and low blood pressure: what to know

Heart failure can reduce the amount of blood pumped forward. Medicines used to reduce strain on the heart or remove extra fluid can also lower blood pressure, particularly after a dose change, illness or poor fluid intake. Dizziness may be worse when standing up. Other causes include infection, bleeding, dehydration or an abnormal rhythm, so a clinician needs the full picture.

If you feel light-headed, sit or lie down and rise slowly once you feel steadier. Keep a record of symptoms, pulse if you have been advised to check it, blood-pressure readings and medicine timing. Contact your GP or heart-failure team if symptoms recur, follow a dose change, or make walking unsafe. Bring all medicines to a GP consultation and ask whether any dose, fluid or salt advice needs review. Avoid driving while faint or significantly dizzy.

Call emergency services for fainting with injury, severe chest pain, severe breathlessness, new confusion, cold clammy skin, or profound weakness. Seek urgent advice for repeated near-fainting, a new irregular heartbeat with dizziness, or inability to stand safely. These symptoms may signal that circulation or heart rhythm needs immediate assessment.

Ask whether your symptoms match a medicine effect or another cause, how and when to check your blood pressure, and what reading or symptom should trigger a call. Clarify which medicines must continue, what to do after vomiting or diarrhoea, and when your treatment plan will be reassessed.