A gastroscopy is one of the most reliable and accurate methods for diagnosing diseases of the stomach, duodenum, and esophagus. Many stomach conditions require this procedure, primarily including gastritis, gastric ulcers, gastric varices, and stomach cancer.

1. Gastritis and Gastric Ulcers: When you have conditions like acute or chronic gastritis or gastric ulcers, the lining of your stomach can be damaged in areas like the antrum, body, cardia, or pylorus. A gastroscopy is needed because it allows the doctor to get a clear, direct look at your stomach lining. This helps accurately determine if there is damage and precisely identify the location of the gastritis or ulcer, as well as assess the ulcer’s size and number.
2. Gastric Varices: If gastric varices, which are often caused by liver cirrhosis, start to bleed, a gastroscopy is necessary. The procedure not only pinpoints the exact cause and location of the bleeding but also allows the doctor to stop the bleeding right then and there. Treatments like band ligation, or injecting clotting or hardening medicines can be performed during the scope. This immediate action is crucial to save the life of someone experiencing massive bleeding.
3. Stomach Cancer: For persistent stomach issues that don’t follow a usual pattern or where the pattern has changed—especially a type of gastritis in the stomach body accompanied by severe anemia, or a large gastric ulcer—there may be a concern about cancer. A gastroscopy is required in these cases. During the procedure, the doctor can take small tissue samples (a biopsy). This is key for early detection of stomach cancer or precancerous changes, leading to earlier diagnosis and timely treatment, which greatly improves the chances of a cure.