Heartburn happens when the valve between your stomach and oesophagus relaxes or weakens, letting acidic stomach contents flow back up (acid reflux). Common triggers include big meals, lying down soon after eating, fatty or spicy food, caffeine, alcohol, smoking, being overweight, and pregnancy.
For occasional symptoms, simple changes often help: eat smaller meals, avoid eating within 3 hours of bed, raise the head of the bed, and limit known trigger foods. Over-the-counter antacids or acid reducers may give relief, but use them as directed and ask a pharmacist if you are unsure.
See a doctor if heartburn happens two or more times a week, lasts despite treatment, or comes with difficulty or pain when swallowing, unintended weight loss, vomiting, black or bloody stools, or anaemia. Seek urgent care or call your local emergency number if you have chest pain with sweating, breathlessness, or pain spreading to the arm or jaw, since this can mimic or signal a heart problem.