Cancer is not sudden, but a gradual process. It takes twenty or thirty years for lung cancer to be advanced. Strong people get cancer not suddenly, but without timely examination and early detection. People who look strong, if the detoxification channel is blocked, not found in time, and there are no other weak parts to detoxify, it is likely to accumulate in parts that are not easy to detoxify and become tumors! In fact, the cancer we have has nothing to do with our physical fitness. It's not that you can't get cancer if you have good physical fitness, so it's a misunderstanding that you shouldn't get cancer if you have good physical fitness.
People in good health often don't get sick or take medicine, and their immunity is high. But because the toxins in the body can't be discharged, the bacteria can't be killed. After a long time, immunity will be reduced. On the contrary, those who are often ill will go to the hospital if they are not feeling well. People who are often sick are more anxious about their physical condition than those who are not often sick, and they are afraid that they are sick. When people with poor constitution are weak and sick, they spend more time in the hospital and receive various examinations. Once they find the problem, they will deal with it in time. However, people with good physical fitness sometimes ignore these. I don't think it's necessary to check.
Environmental factors actually include physical, chemical and biological factors, and some cancers are the result of accumulation and exposure of environmental pathogenic factors. For example, air pollution will increase the prevalence of lung cancer, and new house decoration pollution will increase the prevalence of childhood leukemia.