Habit is actually one of the main reason why people experience acid reflux.

Acid reflux happens when the lower esophageal sphincter (the valve that keeps food within the stomach, and away from the areas above [e.g. esophagus, larynx, mouth, nasal cavity]) fails and opens up, thus, causing the acid to rise up through the esophagus, therefore burning the esophageal lining, and/or laryngeal area, even until the oral and nasal cavities, and causing the sensation called "heartburn".

A number of incidence of heartburn is mainly because of habit. Yes, that simple habit of lying down (whether it be the bed or the sofa) after eating. This simple habit places great pressure on the lower esophageal sphincter which at times, and we could expect, would eventually fail, thus initiating the motion of events stated above. Other activities could also result to a weakening of this sphincter muscle, which, would result in the same thing.

So a solution could be as simple as: DO NOT LIE DOWN AFTER EATING. Wait for at least 45 minutes before doing so. This period would have allowed a portion of what we have eaten to be digested, thus lightening the load on the stomach, and consequently, on the sphincter as well.

If you cannot avoid lying down, then do not recline in a 180 degree lying position. Rather, recline in a half-lying position, around 90-135 degrees. That way, you get to rest but at the same time, do not place pressure on your lower esophageal sphincter by forcing it to trap all that food away from the esophagus. Sit on the couch, or put pillows by the headboard so as not to tire your back while your bidding time.

If you know that you have never developed this habit, or that your acid reflux persists, proceed to consult a medical professional.

A good health to everyone.

Cheers!