What should you know about caffeine nausea?

You may notice queasiness, stomach discomfort, shakiness, a fast heartbeat or an urge to use the toilet. Coffee and energy drinks can also aggravate acid reflux or gastritis in some people. Nausea that follows a shared meal, fever or diarrhoea may have another explanation, such as food poisoning or gastroenteritis, rather than caffeine itself.

Pause caffeine and take small sips of water. Once your stomach settles, try a light meal such as toast, rice or yoghurt if these suit you. Avoid more caffeine, alcohol and very rich foods for the rest of the day. If you want to reduce regular caffeine use, tapering gradually may be more comfortable than stopping abruptly. Record the drink, amount, timing and symptoms so a clinician can see a pattern.

Seek urgent medical help for severe or persistent abdominal pain, repeated vomiting, blood in vomit or stool, fainting, confusion, trouble breathing or signs of dehydration such as very little urine. Arrange medical advice if nausea keeps returning, prevents normal eating or drinking, or occurs without caffeine. A clinician can assess reflux, gastritis, gallstones and other causes.

Ask whether your symptoms fit caffeine sensitivity, reflux or gastritis; whether any medicines or supplements could be contributing; and how to reduce caffeine while maintaining hydration and regular meals.