Heart constantly racing: what should you know?

Palpitations can feel like pounding, fluttering, skipped beats, or a rapid pulse. They may follow exertion, fever, poor sleep, caffeine, nicotine, alcohol, or emotional strain. [Dehydration](/conditions/dehydration/), low blood sugar from [Hypoglycaemia](/conditions/hypoglycaemia/), [Hyperthyroidism](/conditions/hyperthyroidism/), and [Iron Deficiency Anaemia](/conditions/iron-deficiency-anaemia/) can all place extra demand on the heart. [Atrial Fibrillation](/conditions/atrial-fibrillation/) is one rhythm problem that can cause an irregular, racing sensation. A sensation alone cannot identify the cause.

Sit down, breathe slowly, and note when the episode began, how long it lasts, whether the rhythm feels regular, and what you were doing beforehand. Drink fluids if you can do so safely, and avoid stimulants until you have advice. Do not stop prescribed treatment without guidance. Arrange an appointment if racing is persistent, recurrent, or accompanied by tiredness, weight change, thirst, or reduced exercise tolerance. A clinician may check your pulse, blood pressure, medicines, and heart rhythm.

Seek emergency care for a racing heartbeat with chest pain, severe breathlessness, fainting, confusion, or marked dizziness. Get prompt assessment if the rhythm remains fast at rest, starts suddenly and does not settle, or occurs with new weakness. People with known heart disease or symptoms of [Heart Failure](/conditions/heart-failure/) should use their clinician's urgent-care plan.

Ask whether you need an ECG or blood tests, whether a medicine or stimulant could be contributing, and how to distinguish an irregular rhythm from a stress response.