Any type of hernia occurs when a part of an organ pokes through a tear that appears in the muscles near it. In the hiatal hernia's case, the upper side of the stomach gets in the chest through an opening in the diaphragm called the hiatus. The diaphragm is the muscle that separates the thoracic cavity from the abdomen, and the hiatus is an orifice in the diaphragm through which the esophagus passes in order to reach the stomach.

When hiatal hernia appears, the upper stomach and the end of the esophagus slip up through the hiatus because it has become weakened. This is called a sliding hiatal hernia. Most of the hiatal hernias are sliding hiatal hernias, but a few people suffer from a different form, called paraesophageal hernia, which is slightly more dangerous because the stomach can get strangled. Some call it strangled hiatal hernia for this reason. In paraesophageal hernia, the upper stomach and the esophagus don't slide through the hiatus together like in sliding hiatal hernia, but a little part of the stomach slips through it and can strangle the esophagus and shut its blood supply off.

The exact cause of hiatal hernia is not entirely known. It may happen after an accident where the chest or the abdomen of the patient is hit, or if the pressure inside the abdominal cavity is increased by repeated coughing or during pregnancy.

Hiatal hernia doesn't cause any symptoms or trouble in the body, so in most cases people have it and they don't even know about it, but they aren't exposed to any risks. The only time when treatment is required is when strangulation occurs. In this case the patient needs surgery to put the stomach back in its normal position.

Hiatal hernia surgery can be done with the help of the laparoscope, an instrument used in many types of surgeries, that enables the doctor to operate without making a large incision in the chest, but through a very small one.

So, most of the people that have hiatal hernia can easily live with it without experiencing any problems, but if you know that you have it and you start to feel pain in the abdomen often or maybe even vomit, you may be in the danger of a strangulation, so consult your doctor for an accurate diagnosis.