When should you see a doctor about palpitations?

Palpitations are an awareness of the heartbeat: it may feel fast, forceful, fluttering, or uneven. Triggers can include stress, poor sleep, caffeine, fever, dehydration, or low blood sugar. Anaemia and hyperthyroidism can also make the heart beat faster. An irregular rhythm such as atrial fibrillation is another possibility. Less commonly, symptoms may occur alongside heart failure, particularly when breathlessness, ankle swelling, or reduced exercise tolerance is present.

Stop strenuous activity, sit somewhere safe, and note the start time, what the rhythm feels like, and how long it lasts. Record recent caffeine, medicines, illness, stress, meals, and fluid intake. Avoid driving if you feel faint. Arrange a routine appointment for repeated episodes even if they stop, because an examination and an ECG may be needed; a monitor can capture an intermittent rhythm.

Call emergency services for palpitations with chest pain or pressure, severe breathlessness, fainting, new confusion, or collapse. Get urgent medical advice for a sustained very fast or irregular heartbeat, especially with weakness or light-headedness. Do not wait for an episode to pass when symptoms are severe or occur in someone with known heart disease.

Ask whether your symptoms need an ECG, blood tests for anaemia or thyroid problems, or a longer heart monitor. Tell the clinician about family heart history, prescribed and non-prescribed medicines, stimulant use, and whether the sensation starts suddenly or builds gradually.