Why do I get heartburn from water?

Water is pH-neutral, so when it burns, the water is the messenger, not the acid. The burn in heartburn is always stomach acid reaching the oesophagus - the NHS describes indigestion and heartburn as stomach acid irritating the stomach lining or throat, felt after eating or drinking. Water sets it off through mechanics. Volume: a large glass downed quickly stretches the stomach, raising pressure on the valve at its top, and if that valve is already lax, acid splashes upward - chugging half a litre on a full stomach is the classic. Timing: drinking a lot right before lying down gives acid a horizontal runway. And sensitivity: if reflux has already irritated your oesophagus, even plain water washing over raw tissue can sting and feel like burning. Carbonated water adds gas pressure on top, which is why sparkling water triggers more people than still. The fixes follow directly: sip steadily through the day instead of bolting big glasses, keep the last big drink an hour or more before bed, raise the head of the bed if nights are the problem, and notice whether the real pattern is water-after-coffee, water-after-wine, or water-on-a-stomach-full-of-curry - the water often takes the blame for its companions. See a pharmacist about a short course of antacid or alginate if it is frequent. See a GP if heartburn happens most days, needs constant antacids, comes with difficulty swallowing or food sticking, or with unintentional weight loss - persistent reflux and swallowing changes are review-worthy, not self-treat-forever territory. Pymander is a free AI doctor, 24/7 by text, that can help you map the trigger.