What causes palpitations?

Palpitations are an awareness of your heartbeat. You may notice pounding in your chest, a fast rhythm, fluttering, thumping in your neck or a sensation of a missed beat. They can happen at rest or during activity and may last moments or longer.

Common triggers include coffee, energy drinks, nicotine, alcohol, intense exercise, lack of sleep and emotional strain. Fever and some medicines, including decongestants, can also make the heartbeat more noticeable. Dehydration can present with palpitations, and hypoglycaemia can present with palpitations alongside sweating, shaking or confusion. Some people with generalised anxiety disorder or panic disorder experience palpitations during episodes of anxiety or panic.

Heart rhythm conditions such as atrial fibrillation can present with palpitations. Hyperthyroidism and iron deficiency anaemia can also present with a racing or forceful heartbeat. These possibilities cannot be distinguished reliably from the sensation alone.

Pause and sit somewhere safe. Note when the sensation began, how long it lasted, whether the rhythm felt regular or irregular, and what you were doing beforehand. Record associated symptoms and recent caffeine, nicotine, alcohol, illness, stress, new medicines or missed meals.

Arrange a clinical review if palpitations recur, last longer than expected, disturb sleep or occur with reduced exercise tolerance. A clinician may check your pulse and blood pressure, review medicines and arrange an electrocardiogram or blood tests based on your symptoms.

Seek emergency help if palpitations are accompanied by chest pain or pressure, severe shortness of breath, fainting, collapse, marked dizziness or new weakness. Seek prompt assessment for a sustained fast or irregular heartbeat, especially if you have known heart disease or symptoms of heart failure such as breathlessness when lying down or new swelling.

Do not drive yourself if you feel faint or seriously unwell. If the episode has stopped but the warning symptoms occurred, contact a healthcare service promptly and describe exactly what happened.

Ask: Could my symptoms be related to a heart rhythm, thyroid problem, anaemia, dehydration or low blood sugar? Do any of my medicines or supplements contribute? Would an electrocardiogram or monitoring during an episode help? Which symptoms should prompt emergency care?