In cases where gastroscopy has been performed recently and there are no organic lesions, doctors do not recommend further gastroscopy. People with serious heart and lung diseases are also not suitable for gastroscopy. This is because such patients cannot tolerate it and will have serious conditions, people suspected of having gastric perforation are not suitable for gastroscopy, and also people with corrosive esophagitis are not suitable for gastroscopy. Gastroscopy is a kind of endoscopy and a common clinical examination, mainly for the esophagus, stomach and duodenum. Gastroscopy allows clear observation of the esophagus, stomach, and duodenum, and staining of suspicious areas and taking biopsy tissue for pathological analysis.