Carcinoembryonic antigen above 200 μg/L may be caused by cancer or other benign diseases. Carcinoembryonic antigen is a broad-spectrum tumor marker, and its elevated level can be seen in many malignant tumors, such as gastric cancer, colorectal cancer, pancreatic cancer and so on. However, carcinoembryonic antigen has poor specificity and is difficult to diagnose at an early stage, so it cannot be used as the basis for confirming the diagnosis of malignant tumors, but can only be used as a reference for diagnosis. Carcinoembryonic antigen is mostly used to assess the prognosis of patients with malignant tumors and to monitor tumor metastasis or recurrence. Elevated carcinoembryonic antigen does not necessarily mean that the patient has cancer, but can also be elevated in certain benign diseases, such as hepatitis, pancreatitis, cirrhosis, etc. The level of carcinoembryonic antigen can also be elevated in some benign diseases. There is no clear line between benign and malignant diseases that cause elevated carcinoembryonic antigen, so an elevated carcinoembryonic antigen of 200ug/L alone cannot determine whether the disease is benign or malignant. The diagnosis of cancer requires comprehensive consideration of clinical manifestations, imaging results, tumor marker levels and pathological examination, among which pathological examination is the gold standard for diagnosis. Therefore, it is recommended that patients go to the hospital as soon as possible, ask professional doctors to evaluate their conditions, improve relevant examinations such as chest and abdominal CT, gastrointestinal microscopy, etc., so as to promptly identify the causes and then treat them accordingly.