Why do people get cancer? The answers are varied: some say it’s genetic, some think it’s exposure to carcinogens, some think it’s environmental pollution, and some blame “bad luck”. …… The answer may surprise many people: chronic infection. Cancer is a degenerative disease, and the aging population is a major factor. As the elderly population continues to increase, the incidence of tumors is also increasing year by year. Diet, environmental pollution, and poor lifestyle habits such as sedentary lifestyle and smoking in modern life can also increase the risk. However, a recent survey on the attribution of environmental and behavioral risk factors to the Chinese population found that: chronic infection is the leading cause of cancer incidence and death in Chinese patients, accounting for 29.4%; followed by active and passive smoking, accounting for 22.61%; and various other factors such as insufficient consumption of fruits and vegetables, alcohol consumption, occupational exposure and environmental pollution. Chronic infections cause cancer deaths in 32% and 25% of men and women, respectively. In a sense, some cancers are “infectious”. In China, hepatitis B/C virus, Helicobacter pylori (HP), human papillomavirus (HPV) and EBV are the most common cancer-causing infections. China is a “hepatitis powerhouse” and the majority of patients with primary liver cancer are associated with hepatitis B and C virus infection. They evolve into cirrhosis through acute and chronic inflammation, and in some cases can eventually lead to liver cancer. Helicobacter pylori is the most common type of infectious bacteria with a prevalence of 50% to 60% in the population, which may cause gastritis and peptic ulcers, and long-term infection may develop into gastric cancer. The bane of cervical cancer and its precancerous lesions has been proven to be human papillomavirus infection, which is transmitted through sexual contact. The high incidence of nasopharyngeal cancer, on the other hand, is not unrelated to EBV infection. Although infection and cancer are not directly causally related and do not “kill” each other, the germs can lurk in our bodies and wait for an opportunity to strike. This process takes about 10 years or more, and if we can interrupt their spread and eliminate them in the cradle, we can effectively prevent cancer from occurring. First, get vaccinated. Data from Taiwan show that since 1984, 95% of infants and children were vaccinated against hepatitis B. After 20 years, the number of hepatitis B carriers dropped from 10% to 20% to 0.2%, and the incidence of liver cancer was reduced by 70% to 80% accordingly. Second, early treatment. H. pylori can be completely eradicated through the combination of antibiotic treatment, which not only relieves gastritis and gastric ulcer, but also plays a good role in resisting further development of gastric cancer. Again, get screened. women over 30 years old, make sure to get regular cervical screening. Also protect yourself by paying attention to using condoms, not having sex too early, limiting the number of sexual partners, etc. Finally, split meals. H. pylori and other germs are highly contagious and can be transmitted through hands, food and utensils, so it is best to implement a meal sharing system, use communal chopsticks and spoons when having meals together, and isolate infected people in the family.