However, they can occasionally be a sign of a problem in the organ.
They can be triggered by a rush of adrenaline, spicy food, medicines or anxiety. In some cases they indicate arrhythmias, heart rhythm problems.
Those who experience regular palpitations accompanied by symptoms such as dizziness or blackouts will have an electrocardiogram examination and may be sent to specialists for further tests.
Common conditions include atrial fibrillation, which causes an abnormally fast heart rate. A major cause of stroke, it affects 800,000 people in the UK, the majority of whom are aged 55 or over. Supraventricular tachycardia (SVT) is similar, although the heart rate is usually steady rather than irregular. Episodes of SVT usually settle down without treatment.
Ventricular fibrillation, a rapid and disorganised rhythm of heartbeats, occurs when the electrical activity of the heart becomes so chaotic that the heart stops pumping. It leads to loss of consciousness and sudden death if not treated immediately.