Cancer refers to a malignant and aggressive disease formed by abnormal cell proliferation and differentiation. The causes of cancer are very complex. It is currently believed that the occurrence of cancer is mainly related to factors such as heredity, viral infection, bad living habits or hobbies, and environmental pollution. Some special tumorigenic diseases may have special pathogenic factors, for example, the occurrence of endometrial cancer and cervical cancer both have some correlation with the number of pregnancies and births. It is unscientific to simply assume that drinking water from a glass can cause cancer. Drinking water not only from glass, but also from cups made of other materials, is generally not correlated with the development of cancer. Patients should not blindly believe in certain cancer-causing rumors when they have unexplained symptoms such as lumps, pain, ulcers, bleeding, etc. They need to go to regular hospitals in a timely manner, follow the diagnostic advice of specialists, complete the relevant examinations, make a clear diagnosis, and have regular follow-ups.