Causes of Palpitations at Rest

A quiet setting can make normal beats more noticeable, while stress hormones, poor sleep, nicotine, alcohol, and stimulant medicines can change the sensation. Fluid loss or low blood sugar may make the heart beat faster. Anaemia reduces oxygen delivery, so the heart may work harder; an overactive thyroid can also increase heart rate. Atrial fibrillation and other rhythm disturbances may feel irregular, fluttering, or forceful. Heart failure can cause palpitations alongside breathlessness, swelling, or reduced exercise tolerance. The feeling alone cannot identify which explanation applies.

Sit quietly and note the start time, duration, regularity, pulse if you can check it safely, recent food and drinks, medicines, and accompanying symptoms. Avoid extra caffeine, nicotine, and recreational stimulants while arranging assessment. A clinician may perform an examination, blood tests for anaemia, thyroid function, or glucose, and an ECG; an ambulatory monitor can capture episodes that come and go. Do not stop prescribed medicine without advice.

Call emergency services for palpitations with chest pain, severe breathlessness, fainting, collapse, new weakness, confusion, or a sustained very fast or irregular heartbeat. Seek prompt review when episodes are new, recurrent, worsening, triggered by exercise, or linked with swelling or breathlessness when lying down. A family history of sudden cardiac death also warrants careful medical assessment.

Ask whether you need an ECG or monitor, which blood tests are appropriate, whether any medicine or supplement is a trigger, and which pulse or symptom changes should prompt urgent care.