Carcinoembryonic antigen 500ng/ml is considered high. Carcinoembryonic antigen is a tumor marker, and a level of 500ng/ml is considered high, about 100 times the normal value. Such a test result may indicate rectal cancer, stomach cancer, pancreatic cancer, small cell lung cancer, medullary thyroid cancer, breast cancer, etc. However, the disease cannot be determined on the basis of this item. Some benign diseases can also lead to elevated carcinoembryonic antigen, such as benign tumors, colitis, pancreatitis, etc., but usually it is slightly elevated. In order to understand the disease, it is necessary to do further examination, can not rely solely on the results of this examination to determine the disease, the patient should do pathological biopsy, CT examination, urine routine, blood routine and other related examinations. Cancer patients should pay attention to the maintenance, not to eat greasy and spicy food, such as chili, tobacco and alcohol, do not overwork. Cancer patients should actively consult the doctor, do not blindly take medication, and follow the standardized treatment.