Hello Shaukat, Thanks for coming to HCM. Hiatus hernia is a condition when a part of stomach protrudes through diaphragm into the chest. Just to help you understand -- Diaphragm is a thick membrane/sheet-like which divides chest and abdomen cavities. It has got some openings to allow pass important structures, blood supply etc from one cavity to other, Esophagus (food pipe) is one of them. Different parts of stomach are specialized to secret different juices to help break down & digest food that we consume. The junction of esophagus & stomach has valve like rings which regulates passage of contents from esophagus to stomach & stomach to esophagus (reverse direction). In general, these rings prevent the contents of stomach from entering back in esophagus, and when herniated, the ring slides in chest, and the barrier for reflux of stomach content to esophagus gets disrupted. Since the size/cavity of stomach is wider than esophagus, if it protrudes in chest, it becomes like a small pouch in chest. Commonly, hiatus hernia is caused due to sliding of stomach through diaphragm. The symptoms this can produce depends on how much of stomach part has herniated and are almost always those of gastro-esophageal reflux disease (GERD). Common symptoms are heart-burn, regurgitation, and nausea. So, to answer your question, acid reflux is one of the symptom of hiatus hernia, which is diagnosed by endoscopy of upper gastric tract. In X-rays and endoscopy, hiatus hernia appears like a sac, sometimes it is visible only while swallowing (as stomach part gets pulled up which is a normal mechanism during swallowing). Generally, the symptoms are confused with heart/lung problems and doctors always investigate to rule out those reasons. Medicinal Treatment of hiatus hernia is almost same as GERD but if severe unresponsive to medicines, surgical correction might be required. You should consult a gastroenterologist for endoscopy if not done yet. Based on the findings, he will advice you best possible management. Wish you quick recovery!