Can dehydration cause palpitations?

Palpitations can feel like racing, pounding, fluttering, or skipped beats. Fluid loss from sweating, fever, vomiting, or diarrhoea may make them more noticeable, especially with thirst, dry mouth, dizziness, weakness, darker urine, or reduced urination. Caffeine, stress, fever, low blood sugar, anaemia, thyroid disease, and rhythm problems can also contribute. Dehydration should not be assumed when palpitations are new, recurrent, or unrelated to fluid loss.

Stop exertion, sit somewhere cool, and breathe slowly. Take small sips of water if you are awake, able to swallow, and have no fluid restriction. Avoid caffeine, alcohol, nicotine, and strenuous activity until the sensation settles. Note when it began, how long it lasted, whether the rhythm felt regular, and what preceded it. [Dehydration](/conditions/dehydration/) can be one contributor, while [Generalised Anxiety Disorder](/conditions/generalised-anxiety-disorder/) may cause repeated awareness of the heartbeat without proving a heart rhythm disorder.

Call emergency services for palpitations with chest pain, severe breathlessness, fainting, confusion, new weakness, or a sustained very fast or irregular heartbeat. Seek prompt medical assessment for episodes that recur, occur during exercise, wake you, or continue after rest and fluids. A clinician may consider [Atrial Fibrillation](/conditions/atrial-fibrillation/), [Heart Failure](/conditions/heart-failure/), [Hyperthyroidism](/conditions/hyperthyroidism/), [Hypoglycaemia](/conditions/hypoglycaemia/), [Anaemia](/conditions/anaemia/), or [Iron Deficiency Anaemia](/conditions/iron-deficiency-anaemia/) based on the full history and examination.

Ask whether you need an ECG, blood tests, or monitoring, and whether any medicine or stimulant could be involved. Describe your pulse sensation, episode timing, triggers, associated dizziness or breathlessness, fluid losses, caffeine intake, and family history of heart rhythm problems.