Early detection of cancer is very important because early detection offers the hope of cure. However, early detection is mainly from two aspects: 1. To recognize the characteristics of early cancer. For example, digestive tract tumors should pay attention to the fact that if blood in stool appears, it is important to actively seek medical consultation. Some patients who have blood in stool think it is hemorrhoids or anal fissure, and need to seek medical consultation in time to do so. Many patients who had hemorrhoids and anal fissures in the past can develop bowel cancer at the same time, and this may delay the patient’s timely detection of cancer due to the hemorrhoid problem. In addition, the nature of stool may change, such as round banana stool becomes trigeminal stool, which may also be a phenomenon of intestinal cancer. Patients with lung cancer may have cough and blood in sputum, and some patients may have mild chest pain, which also needs attention. Patients with esophageal cancer may also experience pharyngeal discomfort and dysphagia in the early stage. Patients with liver cancer will experience abdominal distension, discomfort and indigestion. Once there are symptoms, you need to go to the hospital for further examination in time to avoid the disease from developing forward so as to facilitate early detection of cancer. 2. For high-risk groups, you should actively do screening, especially for those over 40 years old, you should have annual physical examination. For example, the high-risk group of lung cancer, defined as 55-74 years old, every 30 pack years of smoking history, years multiplied by the number of packs smoked, if smoking 15 years, 2 packs a day, that is 30 packs a year, such a group is a high-risk group. It is recommended to go for annual lung cancer screening and do low-dose spiral CT, which can detect lung cancer and reduce the mortality rate of lung cancer by more than 20% compared to patients who have chest X-ray. Therefore, early examination and early detection are very important, and older patients must have regular medical checkups.