Fasting and heart palpitations

When you eat less or drink less, your body may release stress hormones to maintain energy and circulation. This can make the heartbeat feel fast, forceful or uneven. Losing fluid can also reduce circulating volume, encouraging a faster pulse. Low blood sugar may come with shakiness, sweating, weakness or irritability. Caffeine, nicotine, anxiety and a sudden change in your usual routine can add to the sensation. Palpitations can also occur with conditions such as Hypoglycaemia, Anaemia, Hyperthyroidism or Atrial Fibrillation; a symptom alone cannot identify the cause.

Plan fluids around the fast if your health plan allows it, and avoid excess caffeine or nicotine. Rise slowly, rest in a cool place and note when the sensation began, how long it lasted, your activity and any associated symptoms. If you have diabetes, follow your clinician's instructions for glucose checks and medication; do not change doses independently. Repeated episodes deserve a review, particularly if you have known heart disease, Heart Failure, thyroid disease or anaemia.

Seek emergency care for palpitations with chest pain, fainting, severe breathlessness, new confusion or marked weakness. Arrange prompt medical advice when episodes are new, keep returning, last longer than expected, occur with dizziness, or feel distinctly irregular. A clinician may check your pulse, blood pressure, heart rhythm and blood tests, then advise whether fasting is appropriate for you.

Could my symptoms relate to dehydration, glucose changes, anaemia, thyroid activity or an abnormal rhythm? Should I adjust the timing of medicines or monitoring during a fast? What symptoms mean I should stop fasting and seek help?