A very small percentage of diffuse-type gastric cancers (see Histopathology below) arise from an inherited abnormal CDH1 gene. Genetic testing and treatment options are available for families at risk. Other
Other risk factors include diabetes, pernicious anemia, chronic atrophic gastritis, Menetriers disease (hyperplastic, hypersecretory gastropathy), and intestinal metaplasia.In addition, Foxp3 polymorphism (rs3761548) might contribute to gastric cancer development through influencing Treg cell activity. Diagnosis
To find the cause of symptoms, the doctor asks about the patients medical history, does a physical examination, and may order laboratory studies. The patient may also have one or all of these exams:

Gastroscopic exam is the diagnostic method of choice. This involves insertion of a fibre optic camera into the stomach to visualise it. Upper GI series (may be called barium roentgenogram)
Computed tomography or CT scanning of the abdomen may reveal gastric cancer. It is more useful to determine invasion into adjacent tissues or the presence of spread to local lymph nodes. Wall thickening of more than 1 cm that is focal, eccentric, and enhancing favours malignancy.In 2013, Chinese and Israeli scientists reported a successful pilot study of a breathalyzer-style breath test intended to diagnose stomach cancer by analyzing exhaled chemicals without the need for an intrusive endoscopy. A larger-scale clinical trial of this technology was completed in 2014.Abnormal tissue seen in a gastroscope examination is biopsied by the surgeon or gastroenterologist. This tissue is then sent to a pathologist for histological examination under a microscope to check for the presence of cancerous cells.
Studies have shown a high occurrence of mental disorders, notably anxiety and depression, amongst patients with dyspepsia; however, there is little evidence to prove causation. Organic Dyspepsia
Esophagitis
Esophagitis is an inflammation of the esophagus, most commonly caused by gastroesophageal reflux disease (GERD). It is defined by the sensation of "heartburn" or a burning sensation in the chest as a result of inappropriate relaxation of the lower esophageal sphincter at the site where the esophagus connects to the stomach. It is often treated with proton pump inhibitors. If left untreated, the chronic damage to the esophageal tissues poses a risk of developing cancer. A meta-analysis showed risk factors for developing GERD included age equal to or greater than 50, smoking, the use of non-steroid anti-inflammatory medications, and obesity. Gastritis
Common causes of gastritis include peptic ulcer disease, infection, or medications. Peptic Ulcer Disease
Gastric and/or duodenal ulcers are the defining feature of peptic ulcer disease (PUD). PUD is most commonly caused by an infection with H. pylori or NSAID use. Helicobacter pylori (H.pylori) infection
The role of H. pylori in functional dyspepsia is controversial, and treatment for H. pylori may not lead to complete improvement of a patients dyspepsia. However, a recent systemic review and meta-analysis of 29 studies published in 2022 suggests that successful treatment of H. pylori modestly improves indigestion symptoms. Pancreatobiliary Disease
These include cholelithiasis, chronic pancreatitis, and pancreatic cancer. Duodenal micro-inflammation
Duodenal micro-inflammation caused by an altered duodenal gut microbiota, reactions to foods (mainly gluten proteins) or infections may induce dyspepsia symptoms in a subset of people.