What is acid reflux disease? what causes it? what structures of the digestive system are involved?

A digestive disease in which stomach acid or bile irritates the food pipe lining. This is a chronic disease that occurs when stomach acid or bile flows into the food pipe and irritates the lining. Acid reflux and heartburn more than twice a week may indicate GERD.Symptoms include burning pain in the chest that usually occurs after eating and worsens when lying down.Relief from lifestyle changes and over-the-counter medications is usually temporary. Stronger medication may be needed.

No it's not a contagious disease

It would be b. distress