A high alpha-fetoprotein does not necessarily indicate a disease. Alpha-fetoprotein is a glycoprotein, mainly synthesized by fetal liver cells and yolk sac. Fetoprotein has a high concentration in fetal circulation and decreases after birth. 2-3 months after birth, fetoprotein is basically replaced by albumin, which is difficult to be detected in the blood, so the level of fetoprotein in adult serum is very low. The normal reference value of serum alpha-fetoprotein is ﹤25μg/L. Higher alpha-fetoprotein may be caused by pathological factors, and elevated alpha-fetoprotein is commonly found in primary hepatocellular carcinoma, hepatoblastoma, gonadal teratoblastoma, testicular carcinoma, ovarian tumor, malignant teratoma, pancreatic carcinoma, gastric cancer, intestinal carcinoma, lung cancer and other diseases. High alpha-fetoprotein can also be caused by physiological factors, and newborns and pregnant women can have high levels of alpha-fetoprotein. Since alpha-fetoprotein is secreted by naïve liver cells of newborn babies, the liver cells of fetuses are not fully developed and differentiated, and secrete a large amount of alpha-fetoprotein, which can enter the maternal bloodstream through the umbilical cord blood, so the serum alpha-fetoprotein level of pregnant women will increase. If the alpha-fetoprotein is high, it is recommended to consult a doctor in time for a clear diagnosis and targeted treatment under the doctor’s guidance.