Heart palpitations for days: what to know

A run of symptoms may follow stress, poor sleep, dehydration, illness, stimulant use, or low blood sugar. It can also occur with anaemia, hyperthyroidism, or a rhythm disturbance such as atrial fibrillation. Heart failure is another condition a clinician may consider when palpitations accompany breathlessness, swelling, or unusual tiredness. The duration alone cannot reveal the cause, and a symptom diary is more useful when it describes what the beat felt like and what you were doing.

Book a medical appointment promptly rather than repeatedly waiting for the episodes to pass. Bring a list of medicines, supplements, caffeine or energy-drink use, recent illness, and any family history of rhythm problems. During symptoms, rest, drink water if appropriate, and avoid strenuous exertion and stimulants. Note your pulse if you can do so safely, but do not delay care to measure it perfectly. An electrocardiogram or longer rhythm monitor may capture an intermittent problem.

Seek emergency help now for chest pain, severe breathlessness, fainting, new confusion, or severe dizziness. Urgent assessment is also needed if a sustained fast or irregular heartbeat is accompanied by weakness or you feel close to passing out. Symptoms that settle still deserve follow-up when they have continued for days.

What rhythm might this represent? Do I need an electrocardiogram, blood tests, or ambulatory monitoring? Could anaemia, thyroid function, hydration, or a medicine be involved?