As the most difficult disease to be cured, everyone talks about cancer, but in fact, some cancers, if detected in time and treated reasonably, patients can survive for a long time. Many tumors are not asymptomatic before they occur. Here are some common signs for early detection and treatment. 1. Unexplained weight loss Without deliberate weight loss, unexplained continuous weight loss or accompanied by indigestion, anemia, weakness, easy fatigue and other symptoms must be identified as one of the manifestations of cancer. 2. Unexplained fever There are many reasons for fever, but if the cause of fever is unknown, especially if the fever is persistent and low, think about the possibility of cancer precursors and make sure to find out the cause, not just use fever-reducing drugs. 3. Change in stool habits If there is a change in the number of stool habits or the nature of stool, such as thin stool, stool with pus, blood or mucus, or alternating constipation and diarrhea, be alert to colorectal cancer. Black stool or tarry stool may reflect bleeding in the upper gastrointestinal tract, and it is necessary to be alert to the possibility of gastric cancer or gastric ulcer. 4.Gastrointestinal symptoms Indigestion and lack of appetite are extremely common, but most of them are functional and last for a short time. 5.Long-standing cough For long-standing dry cough or blood in sputum, especially for those who have a long history of smoking, one should suspect the possibility of lung cancer or throat cancer. Unexplained pain Unexplained pain in any part of the body that is not caused by trauma and lasts for more than a week should be identified in the hospital because it may be a sign of cancer and should not be taken lightly. For example, chronic abdominal pain is a symptom of colorectal cancer, chest pain may be caused by lung cancer, and bone pain may be a symptom of metastatic cancer. Pancreatic cancer may manifest in the upper abdominal region, such as persistent dull pain or colic around the umbilicus or right upper abdomen, which may be paroxysmal or persistent, usually gradually worsening and radiating to the lower back. 7. Persistent hoarseness For hoarseness that lasts for a long time and is difficult to recover, it is necessary to be alert to laryngeal cancer, thyroid cancer, lung cancer and esophageal cancer, etc. 8.Abdominal distension Persistent swelling, pressure and pain in abdomen, gastrointestinal discomfort, difficulty in eating or feeling full easily for several weeks may be a sign of ovarian cancer. 9. Irregular bleeding Abnormal vaginal bleeding between women’s menstrual cycles is likely to be a major sign of endometrial cancer, a common gynecological cancer. As for bleeding in stool, excluding bleeding caused by benign diseases such as hemorrhoids and anal fissure, we should be alert to colon cancer. 10. Swollen lymph nodes The superficial lymph nodes in the neck, behind the ear, groin, etc. often become swollen after infection, but usually the swollen lymph nodes will return to normal after the infection is cured, if the swollen lymph nodes persist or increase in size, you should go to hospital for examination immediately. 11, breast lumps Redness of the breast skin, lumps, especially a rash on the breast, and persistently does not subside, must go to check. In addition, non-lactating women with sunken nipples and overflowing nipples should also pay attention. 12. Testicular changes Testicular cancer is most common in the age group of 20 to 39. Men should self-examine testicular condition every month, including changes in testicular size, the appearance of obvious enlargement or shrinkage, the appearance of masses in the scrotum, and the feeling of scrotal cramps and pains. In particular, feeling of scrotal cramping and persistence for a long time may be the most typical precursor of testicular cancer, which requires blood test and scrotal ultrasound test. 13.Abnormal urination Intermittent painless meatus hematuria is the most common clinical symptom of bladder cancer patients, and kidney cancer patients also have the possibility of hematuria. Older men should also be alert to the possibility of prostate cancer if they have difficulty in urination, feel pain or burning sensation when urinating, and increase the number of night urination. 14. Spontaneous fracture Fracture is a common situation, but if it occurs without external force, then we should be alert to skeletal malignant tumor. Adolescents with non-traumatic pain and swelling at the elbow or knee joint should be careful of leukemia and find out the cause as soon as possible. 15.Enlargement of mole Sudden enlargement of mole, accompanied by itching, breaking, bleeding, pain, or loss of hair on the mole. Be careful of the occurrence of malignant melanoma. 16.Red or white patches and abnormal hard lumps inside the mouth Observe the color, opening and closing activity and shape of the lips first for any differences. Then open the mouth to observe the red lips and the back of the tongue for painless red or white patches and abnormal hard lumps. The inner moving membrane of both cheeks and dental caries should be observed for redness, hardening, thickening and spots (especially white spots). There is also stretching and flipping of the tongue to observe whether there is vibration, asymmetry, unrestrained movement and abnormal color, and whether there is curvature and enlargement of the surface, tip and edge of the tongue. Oral cancer precursors that need to be alerted.