Tumor is a new organism formed when the cells of local tissues lose the normal regulation of their growth at the genetic level under the action of various tumorigenic factors, resulting in abnormal proliferation and differentiation. Once a new organism is formed, it does not stop growing due to the elimination of pathogenic factors, and its growth is not regulated by the normal physiology of the organism, but destroys normal tissues and organs. Cancer is indeed a difficult disease to treat under the current medical level. The reason for the difficulty lies in the fact that there are no signs in the early stage of cancer, and 80% of the patients are already in advanced stage when they are found. However, difficult to treat does not equal to incurable, medical research on cancer treatment is also progressing, surgery, radiotherapy, chemotherapy, comprehensive treatment and other treatment modalities, so that the chances of cancer being cured are greatly improved. Early detection, early diagnosis and early treatment are crucial for cancer patients. Especially when the following characteristics appear, more attention needs to be paid: I. Blood (hemorrhage) In addition to normal menstruation in women, unexplained bleeding from any organ that is prolonged and unresolved may be an early alarm signal of cancer. 1, unexplained nosebleed Excluding trauma, external force, dry weather or high blood pressure caused by a one-time nosebleed, may be nasopharyngeal carcinoma, blood disorders and so on. Coughing up blood, sputum with blood, excluding temporary bleeding caused by dry weather or overwork, which may be lung cancer. Blood in urine If there is hematuria, especially painless hematuria, it may be bladder cancer or kidney cancer. Blood in stool If it is accompanied by change of bowel habit, urgency and heaviness (abdominal pain and embarrassment, desire to defecate, heavy fall of anus and unpleasant stool), it may be the early manifestation of colorectal cancer. Bleeding from nipple: Bloody discharge from nipple of women may be breast cancer or breast duct tumor. Vaginal bleeding after menopause Vaginal bleeding after menopause may be cervical cancer. 2. Lumps (abnormal lumps) 1. Lumps that do not go away for a long time or increase rapidly within a short period of time appear in superficial parts of the body. Cancer tends to be irregular lumps with itching, ulceration and oozing. 2, asymmetric breasts on both sides, irregular lumps, orange peel-like changes, may be breast cancer; goiter, sudden inability to make a sound or voice suddenly become hoarse, in addition to the thyroid gland, but also to the oncology department, so as to avoid thyroid cancer, laryngeal cancer leakage of diagnosis. Third, pain (pain) Long-term and continuously aggravated pain may be the early signals of cancer: 1. Progressively aggravated headache, accompanied by nausea, vomiting (projectile vomiting is more critical), and blurred vision, which may be the manifestation of brain tumor, or it may be caused by brain metastasis from lung cancer. When the above symptoms appear, some patients tend to go to neurology department for medical treatment, but they must consult oncology department after seeing neurology department to check whether there is a brain tumor or not, so as to avoid delaying the time of treatment. 2.Pain, pressure, tightness and hardness in the neck, facial edema, which may be caused by the obstruction of blood return due to the tumor compressing the superior vena cava. Burning sensation at the back of the sternum, unsmooth swallowing and pain, which may be the manifestation of esophageal cancer and cardia cancer, gastric cancer. Four: Fever (fever) Persistent fever, especially low fever, children should be alert to blood system tumors, and adults should be alert to the possibility of liver cancer, kidney cancer and other tumors. Weight loss (weight loss) Unexplained weight loss in a short period of time and progressive decline (excluding hyperthyroidism and diabetes mellitus) may be tumors; if weight loss is accompanied by yellowish skin color and pain, it is necessary to take active examination to exclude tumors such as pancreatic cancer and other tumors.