Basically, heartburn is a digestive condition where stomach acid refluxes and comes in contact with the esophagus. A lot of people experiences heartburn for at least once every month. However, if you continue experiencing heartburn every day, then you are suffering from a chronic or severe type of heartburn, which can prevent you from living a normal life. Smoking also weakens or relaxes the LES as well as certain medications. Pressure on stomach and eating large meals shortly before bedtime can also cause heartburn. Stress will also cause heartburn as this increases acid production and slow down the emptying of the stomach. So, in order to manage heartburn, you may want to start by making some lifestyle changes. This is also the reason why you taste something bitter right after the heartburn episode. So, should you be concerned if you experience heartburn? For starters, heartburn is a major symptom of gastroesophageal reflux disease. And, you need to remember that this can be misdiagnosed because the burning in the chest symptom of heartburn is also a symptom of ischemic heart disease, which is a much more serious illness. And, as you may already know, if the LES is weakened, it may not function properly and will let the stomach acid flow in to the esophagus, which will ultimately cause heartburn. Stress is another known cause of heartburn. It has been found that stress can increase the acid production in the stomach and slows down the emptying of the stomach, causing heartburn. Basically, the sphincter acts as a valve that prevents stomach acid from reaching the esophagus. When it is relaxed or is weakened, stomach acid can get through the sphincter and eventually irritate it and cause heartburn. So, just what causes the sphincter to weaken or relax? There are certain foods that can weaken the sphincter. However, you have to remember that there is such a thing as a chronic heartburn and this may have a negative effect on your life. So, how can you tell if you are already suffering from a chronic heartburn? Well, if you experience heartburn once a month, this is considered to be acute or mild. If you experience heartburn once a week, this is a moderate case of heartburn.