My heart races, thumps or skips

Palpitations are the sensation of your own heartbeat — racing, pounding, fluttering or skipping. They are very common, and in most people they turn out to be harmless.

The difficulty is that they come and go. A standard ECG records about ten seconds, so unless the symptom happens during those ten seconds it will not be captured. That is why monitoring over a day or longer is often the more useful test.

What is worth mentioning early: palpitations that come with blackouts, that happen during exertion rather than at rest, or that occur alongside a family history of sudden death are assessed more urgently.