Alpha-fetoprotein is an acidic glycoprotein synthesized by the liver and yolk sac during early fetal development and disappears shortly after birth. Currently, checking serum methemoglobin is an important clinical indicator for the diagnosis of hepatocellular carcinoma, which is a tumor marker for primary liver cancer. Although methemoglobin is a better indicator for early diagnosis, its clinical significance is still limited. Patients with elevated fetoprotein should not be alarmed because not all patients with elevated fetoprotein are hepatocellular carcinoma. The following measures can be taken: 1. First of all, we should clarify whether there is a history of liver disease and pregnancy. 2.In the monitoring of pregnancy, if methemoglobin is found to be greater than 400μg/L, it often indicates fetal dysplasia, which requires auxiliary examination and timely termination of pregnancy after diagnosis. 3.When low level of methemoglobin is elevated, liver ultrasound, CT and other examinations can be done to determine whether it is benign liver disease or liver cancer. About 10% of normal people may have a slight increase. 4.The detection of methemoglobin may show false positive. When there is an increase of methemoglobin, it can be detected jointly with carcinoembryonic antigen and other tests to improve the sensitivity and specificity. 5, hepatitis, cirrhosis patients also have a transient elevation of alpha-fetoprotein, generally less than 400 micrograms / liter, the duration is generally not more than 2 months, pay attention to the differential diagnosis, regular observation, short-term review. When there is hepatitis, cirrhosis and other diseases, it is also necessary to actively treat the cause, cautiously use drugs for liver damage, you can use symptomatic drugs and pay attention to diet. When there is elevated methemoglobin, do not be overly panic, seek timely medical attention, make further examination and treatment according to the situation, and strengthen observation and regular review after excluding the cause of the disease.