What causes heartburn?

Following are causes of heart burn-
*Coffee, tea, and other drinks that contain caffeine-Caffeine can relax the lower esophageal sphincter (LES), allowing stomach contents to reflux into the esophagus.
*Chocolate-Chocolate contains concentrations of theobromine (a compound that occurs naturally in many plants such as cocoa, tea and coffee plants), which relaxes the esophageal sphincter muscle, letting stomach acid squirt up into the esophagus.
*Fried and fatty foods-These foods tend to slow down digestion, keeping the food in your stomach longer. This can result in increases pressure in the stomach, which in turn puts more pressure on a weakened LES, allowing reflux of stomach contents.
*Tomatoes and tomato-based products-These foods relax the lower esophageal sphincter (LES).
*Alcohol-Alcohol relaxes the lower esophageal sphincter, allowing the reflux of stomach contents into the esophagus. It also increases the production of stomach acid.
*Tobacco-The chemicals in cigarette smoke weaken the LES as they pass from the lungs into the blood.
*Large meals-A full stomach can put extra pressure on the lower esophageal sphincter (LES), which will increase the chance that some of this food will reflux into the esophagus.
*Citrus fruits and juices-These foods relax the lower esophageal sphincter (LES).
*Eating within 2 to 3 hours prior to bedtime-Lying down with a full stomach can cause stomach contents to press harder against the LES, increasing the chances of refluxed food.