A hernia is a bulge. A hiatus is a break or gap. Hiatus hernia is a bulge of the top or your stomach through the diaphragm. The medical solution is to put you on drugs to make your stomach less acid or stop making acid. That treats the symptoms not the cause. The result of less stomach acid is to reduce effective digestion of proteins and fats. Low acid allows yeasts and moulds to enter your small intestine and lead to complications.
Your diaphragm is a big muscle that spreads under your ribs. It helps you to draw air into your lungs by creating a small vacuum when you breathe in or take a breath. It also helps to digest your food by giving you a deep internal massage. Your lungs and heart live the same cavity above your diaphragm. Your stomach, kidneys, liver, spleen, gall bladder, small intestine and large intestine (colon) live below your diaphragm.
The obvious solution is to work on the strength of your diaphragm and find out which foods or drink aggravate you. Many people have said to me that apple cider vinegar really helps their digestion. In common with many fruits it contains malic acid that works with hydrochloric stomach acid to improve digestion. One lady switched to Amla (Amalaki) an Ayruvedic herb similar to gooseberry. It is meant to calm a Pitta personality. Instead it gave her severe heartburn. Gooseberries, along with rhubarb contain oxalic acid that taken over a period of time can lead to heartburn and gallstones.