Acid reflux is an unpleasant condition. Not only is it uncomfortable, but experiencing chronic acid reflux (known as GERD, or gastroesophageal reflux disease) may cause esophageal cancer.
https://www.acsh.org/news/2017/08/01/nexium-and-proton-pump-inhibitors-ppis-all-possible-side-effects-11640
Nexium And Proton Pump Inhibitors (PPIs): All Possible Side Effects