Heartburn is a condition which causes a burning sensation in the chest. This condition can be quite painful, especially if left untreated. In some cases, heartburn can feel as if you were having a heart attack - something which has scared many a patient. However, heartburn is caused by some stomach acid going back up into the esophagus - which should not be the case. Normally, the acid is kept in the stomach by the lower esophageal sphincter, which is a band of muscle which closes automatically. People who suffer from heartburn have a weak lower esophageal sphincter, though, resulting in the backflow of the acid.
Heartburn is not that uncommon, and in fact, many people suffer from it every now and then. For those who have these occasional attacks, it is not much of an issue. Over-the-counter medicine is readily available to deal with the acid. Antacids such as Maalox, Rolaids, and Tums work very well in most cases and will relieve the pain rather quickly. Another group of medication that can treat heartburn are H-2-receptor blockers. Examples are Pepcid AC and Zantac 75. This kind of medicine work for longer lasting relief, but the trade off is that you do not feel the effects immediately.
One reason for the pain associated with heartburn is that the esophagus gets damaged by the acid. If the acid keeps going back up, the esophagus will not have time to heal, making the pain worse. Medication such as proton pump inhibitors can help with this as they stop the production of acid. One example of a proton pump inhibitor is Prilosec OTC.