1.Those who often drink very hot and strong tea often drink high temperature (above 80 degrees Celsius) strong tea, not only easy to scald the esophagus, the formation of chronic ulcers in the esophagus, tannin in tea due to deposition in the injured parts, more likely to stimulate the injured esophageal epithelial cells, prompting chronic ulcers do not heal, leading to cancer. 2, often stay up late cancer cells are formed by mutation in the process of normal cell fission. If there is insufficient sleep at night and the body’s ability to fight diseases is reduced, it will be difficult to control the mutation of cells and form cancer cells. People who stay up late at night often smoke and drink coffee to refresh themselves, which also makes more carcinogens invade the body. 3.People who hold their urine and stool The risk of bladder cancer is directly proportional to the time of urine retention. Urine contains a carcinogenic substance that can invade bladder muscle fibers and make them cancerous. There are more harmful substances in the stool, hydrogen sulfide, fecal odorants and other carcinogens, which can also lead to cancer if they often irritate the intestinal mucosa. 4. Allergic people American scientists surveyed nearly 40,000 people, who have asthma and are allergic to certain drugs or chemical agents, are more prone to cancer than those without allergies. For example, women with allergies have a 30% higher chance of developing breast cancer than normal people; men with allergies have a 41% higher chance of developing prostate cancer than normal people.