HCG, also known as human chorionic gonadotropin, is mainly used to check if you are pregnant and whether you have related diseases, and is widely used in clinical practice. It can be checked by both urine and blood, and there is a difference between these two methods in measuring HCG in the morning or in the afternoon, and generally the morning test is more accurate. If HCG is checked by urine, because of less water at night, the concentration of HCG in the morning urine is higher, which in turn leads to higher HCG value in the morning and helps to determine pregnancy early; while drinking more water during the day leads to low concentration of hormones contained in the urine in the afternoon, so the HCG concentration value in the afternoon will be low and not easy to detect. In addition, HCG can also be checked by blood. The results of this test are more accurate, and the finding of elevated blood chorionic gonadotropin levels indicates that the patient has conceived. The blood HCG test is usually recommended to be taken in the morning before 10:00 am on an empty stomach, so that the indicators are more accurate and can help determine whether or not the pregnancy is present, as well as the growth and development of the gestational sac according to the changes in the values. And if the blood is drawn in the afternoon many people will eat, even if they insist on not eating from the morning to the afternoon, but due to the concentration of blood, it will still have an impact on the HCG test results. If a patient has an abnormally high HCG test after pregnancy, it suggests that the patient has a twin pregnancy or trophoblastic disease; if the patient herself has pregnancy-related trophoblastic disease such as staph or erosive staph, she needs to monitor HCG and observe the effect of treatment; if the patient has an ectopic pregnancy and takes conservative treatment, she also needs to monitor HCG values and observe the effect of conservative treatment.