Carcinoembryonic antigen 15 ng/ml is not serious, but needs to be tested dynamically. Carcinoembryonic antigen should be kept within 5 ng/ml under normal condition, while 15 ng/ml is 3 times beyond the normal range, which is a mild elevation phenomenon, the situation is not very serious, and most of them are considered to be related to benign diseases such as colon polyps, pancreatitis, etc., and need to carry out continuous dynamic testing. If carcinoembryonic antigen continues to rise more than ten times the normal range, it may be related to malignant tumors of the digestive tract and lungs, and the cause of the disease should be determined by CT and MRI of the abdomen and chest, or even biopsy of pathological tissues in a timely manner. Once cancer is confirmed, surgery, radiotherapy, chemotherapy and other anti-cancer treatments should be taken in a timely manner to prevent the condition from worsening and endangering lives.