Many diseases are roaming around the environment now a day. Some have evolved from other diseases; some of these evolved from simpler diseases and after they have evolved they have become more dangerous and complicated. One of these diseases is the peptic ulcer. Peptic ulcer or also known as peptic ulcer disease (PUD) is a type of ulcer that occurs in the area of the gastrointestinal tract that is, most of the time acidic hence, it is extremely pai ful. There are many classifications of ulcer depending on the region or the area of the body where in it is affected. There is the gastric ulcer which is in the stomach area, the duodenal ulcer which is in the duodenum, the esophageal ulcer found in the esophagus and there is the Meckel's diverticulum ulcer found in the Meckel's diverticulum. The pathophysiology of peptic ulcer describes the causes of ulcer, it's evolution as a disease and ways to prevent it and eventually treat it. First we must know how such disease occurs. Since most of the time it occurs in the stomach we might as well focus on that body part. The stomach produces acids to break down the food taken in and eventually digest it. This particular acid or also known as gastric acid is very strong but the stomach and duodenum is able to live with it since it is protected by a lining of mucus. But if that particular lining on the stomach is broken down or eroded thus, the sensitive tissue is below is exposed to the acid. The acid comes in contact into the wall of your stomach or duodenum that damages the part thus, causing ulcer to arise.Many symptoms arise once a person has peptic ulcer. One is abdominal pains, bloating and abdominal fullness, waterbash or the rush of saliva after diluting acid down the esophagus, nausea, hematemesis or when a person starts vomiting blood, melena and rarely ulcer may direct to a much complicated disease called gastric or duodenal perforation, which eventually may direct to acute peritonitis. This time it already very painful and the person would really need to take surgery. This type of illness may cause many types of complication such as gastrointestinal bleeding being the most common complication, perforation which is basically a whole on the wall of the stomach, the ulcer continuing to move and eventually be adjacent to the pancreas and liver and other adjacent organs, scarring and swelling and cancer being the most feared complication. But the pathophysiology of peptic ulcer may involve a much braoder value if take into the next level of necessary actions.