A muscular valve at the bottom of your esophagus normally keeps corrosive digestive juices where they belong – in your stomach. But if you have heartburn, this valve sneaks open at inopportune times, like after a big meal, letting acid go where it doesn’t belong and causing pain that can be mild or so bag you may think it’s a heart attack. Weakening or relaxation of lower esophageal sphincter, the muscular valve at the bottom of your esophagus.
http://www.noahhealth.org/natural-ways-to-relief-heartburn/#fcem
Natural Ways To Relief Heartburn