Gastroscopy is generally not contagious, before the gastroscopy will be checked for infectious diseases, gastroscopy after the instrument will undergo a specific sterilization treatment. Before the gastroscopy, the doctor will let the examinee go for a blood test to exclude infectious diseases such as viral hepatitis B, viral hepatitis C, etc., as well as exclude infectious diseases such as AIDS as well as syphilis, etc., and if there are people with these diseases, the gastroscope will usually be sterilized in a specific process. After the mirror is done, the mirror will be put into a special disinfection room for disinfection, and the disinfected mirror will be put into a sterile cart to ensure that one person and one mirror will be available for the examinee to use, so this disinfection system is very perfect, and there is no cross-infection phenomenon in general. The instruments in the whole endoscopy center are sterilized through strict sterilization, infectious diseases are excluded before being examined, and the instruments after being examined are prepared for complete sterilization, so gastroscopy generally does not cause infectious diseases.