What should you know about hard heart palpitations?

You may feel pounding in your chest, a flutter, a racing sensation or a beat that seems to pause. The sensation can happen when the heart beats faster, more strongly or irregularly. Common triggers include emotional strain, poor sleep, fever, caffeine, nicotine, some medicines and low fluid intake. Anaemia, iron deficiency anaemia, an overactive thyroid, low blood sugar and anxiety can also contribute. Less commonly, an irregular rhythm such as atrial fibrillation or another heart problem needs assessment. A sensation alone cannot identify its cause.

Stop and sit somewhere safe. Breathe slowly and note when the sensation began, how long it lasted, whether the rhythm felt regular, and what you had eaten, drunk or taken beforehand. Avoid caffeine, nicotine, recreational drugs and decongestants until you have advice. Drink fluids if you may be dehydrated and you have not been told to restrict them. Arrange a clinical review if episodes recur, are becoming stronger, or interfere with sleep or activity. A clinician may check your pulse, blood pressure, medicines and an electrocardiogram, with further tests if needed.

Seek emergency help for palpitations with chest pain or pressure, severe breathlessness, fainting, collapse, new confusion or marked weakness. Get urgent assessment if the pounding is sustained and you feel unwell, or if it starts during exertion. Do not drive yourself if you feel faint. Palpitations with swelling, breathlessness when lying down or unusual tiredness also deserve prompt review because they can occur with heart failure.

Could my medicines, thyroid, blood count or blood sugar be contributing? Should I have an electrocardiogram or a monitor to record an episode? Which symptoms mean I should seek emergency help?