The specialist may also conduct a diagnosis where they will test the strength of your LES muscle, which is basically a valve that separates the stomach acid from your esophagus. This test is called esophageal manometry. You may also be subjected to a procedure called the 24 hours pH monitoring. This measures the strength of your stomach acid and a thin tube will be passed through your nose and in to your esophagus. The LES is responsible for keeping stomach acid inside your stomach and if it relaxes, it will open up and allow acid to come in contact with your esophagus. Lastly, you may want to have a supply of antacids ready in case you experience heartburn during the night. Drinking plenty of water can also help neutralize the acid in your stomach. Most drugs of this type may be purchased over the counter and what it does is that it decreases the amount of acid that your stomach produces. Usually, they are taken twice a day and they provide relief from heartburn within 30 minutes of taking it. You have to remember that although it can be purchased over the counter, you still need a doctor s prescription for higher doses. So, what causes stomach acid to flow up to the esophagus? There are several explanations on why this happens but one of the main reasons is the food we eat. You need to know that certain foods increase the likelihood of us experiencing heartburn. So, by changing our diet, you will be able to find relief from heartburn and even decrease its frequency. Most people who experiences frequent heartburn says that this condition can really prevent you from doing your daily activities. In short, heartburn can prevent you from living a normal life. This is why a lot of people buy over the counter medicines to ease the pain caused by heartburn. You have to keep in mind that over the counter medicines can work for mild cases of heartburn but if you are suffering from a severe case of heartburn, then you may want to try consulting your doctor as this may already be a sign of a more serious illness. As a matter of fact, heartburn has nothing to do with the heart. Heartburn is basically a digestive illness that can be prevented or least lessened in its frequency through lifestyle modifications. Heartburn happens when our stomach acid refluxes and comes in to contact with our esophagus. This irritates our esophagus and causes us to feel a burning sensation starting from the diaphragm all the way behind our breastbone.