Many factors may cause tumor marker elevation, including benign diseases such as chronic liver disease, chronic kidney disease, cholelithiasis, diabetes and some drugs, and even factors such as blood sampling and improper preservation of specimens may also cause some tumor marker elevation. The influence of biological factors on tumor markers: PSA increases with age; CA199, CA153, CEA, etc. may increase in the elderly. In some women, CA125 and CA199 can be elevated during menstruation. In pregnancy, AFP and CA125 are significantly elevated. Elevated CEA can be seen in some long-term smokers. Therefore, even normal people with other diseases may have elevated tumor markers, which may be normal again after a period of time. If tumor markers are found to be elevated, do not be overly nervous, but go to the hospital to consult with a specialist to rule out some factors affecting the test results, and then decide whether to test again in 2 to 4 weeks or to do further tests under the guidance of a doctor to find out the cause of elevated tumor markers. A high tumor marker does not necessarily mean that the patient has a tumor during physical examination, but its significance is to suggest. Tumor marker test can only be an auxiliary tool, but it also needs to rely on the mutual cooperation of modern medical imaging (endoscopy), cytopathology and laboratory medicine and clinicians. If tumor markers are mildly elevated (not too much above the normal reference value), the possibility of tumor occurrence is relatively low, and further examination can be considered or dynamic observation. For moderate to severe elevation or persistent elevation of several indicators, the possibility of tumor occurrence is higher, and medical imaging and cytopathological examination should be done as soon as possible. Similarly, negative tumor markers do not completely exclude associated tumors. For example, among liver cancer patients, the positive rate of the liver cancer marker alpha-fetoprotein (AFP) is only 79% to 90%, which means that there are still 10% to 30% of primary liver cancer patients with normal or only mildly elevated AFP. Subjects should also be aware of this.