What should you know about heart rate palpitations?

You may notice the sensation in your chest, neck or throat, while your pulse may be normal or genuinely fast. Palpitations can happen at rest, during activity or after an emotional shock, so the sensation alone does not identify its cause.

Common triggers include stress, anxiety, lack of sleep, strenuous exercise, fever, caffeine, nicotine, alcohol and some medicines. Dehydration, low blood sugar, anaemia and an overactive thyroid can also make the heartbeat more noticeable. A heart rhythm problem such as atrial fibrillation is another possible explanation, particularly when the rhythm feels irregular.

Most brief episodes are not caused by a dangerous heart condition, but the pattern matters. Note whether the sensation starts suddenly or gradually, how long it lasts, whether it is regular or uneven, what you were doing, and any symptoms that occur with it. A clinician may check your pulse, blood pressure, heart rhythm and medicines, and may arrange an electrocardiogram or blood tests.

Stop strenuous activity and sit somewhere safe. Breathe slowly and steadily, and avoid caffeine, nicotine, alcohol and non-prescribed stimulants until the episode settles. Drink water if you may be dehydrated and can safely swallow. Do not take another person’s heart medicine or try forceful neck massage.

Arrange a medical appointment if palpitations keep returning, last longer than usual, happen with exercise, disturb sleep, or began after a medicine change. Bring a list of medicines and supplements, and record the timing, duration, pulse if you can measure it safely, and associated symptoms.

Seek emergency help now if palpitations are accompanied by chest pain or pressure, severe breathlessness, fainting, near-fainting, confusion, or marked weakness. Get urgent assessment for a very rapid or irregular heartbeat that does not settle, especially if you have known heart disease or are pregnant. Do not drive yourself if you feel faint or unwell.

A clinician should also assess palpitations with new ankle swelling, breathlessness when lying down, or unusual tiredness, because these can occur with heart failure or another medical problem.

Ask: Could a medicine, thyroid problem, anaemia, dehydration or low blood sugar explain these sensations? Do I need an electrocardiogram or a longer rhythm monitor? Which symptoms should send me to emergency care? Is exercise safe while this is being assessed?