CEA is carcinoembryonic antigen, carcinoembryonic antigen >5ng/mL will have the possibility of cancer, but the indicator is high does not necessarily have cancer, need to be analyzed in conjunction with other tests. Carcinoembryonic antigen is an acidic glycoprotein, which can exist on the surface of cancer cells and be secreted into the surrounding body fluids, and it is a common tumor marker, and its normal value is 0~5ng/mL, and if it is >5ng/mL, then it is on the high side, and it is suspected that there is a possibility of cancer. If the value of carcinoembryonic antigen is tens or hundreds times higher than the normal value, cancer will be highly suspected, but this result alone is inaccurate, and can only be used as an auxiliary diagnostic basis, but also combined with the routine blood, pathological examination, CT and other examinations to determine whether there is cancer. Carcinoembryonic antigen may be high in some people who smoke, or the results may be high due to the different measuring instruments and standards of the testing organizations, therefore, a high level of the indicator does not necessarily mean that you are suffering from cancer. In case of high carcinoembryonic antigen, the results should be combined with other tests under the guidance of a doctor to determine whether the results are clinically significant.