HCG dilution means that when the HCG in the blood exceeds a certain concentration, the result of direct measurement of HCG in the blood using reagents alone cannot give an accurate value, so it is necessary to dilute the blood to a certain multiple and then detect the value of diluted blood HCG and multiply it by its multiple, which is the value of HCG in normal blood. In clinical practice, the HCG test is mainly used for the diagnosis of intrauterine pregnancy, ectopic pregnancy, and biochemical pregnancy. In addition, for trophoblastic tumors, it also plays a diagnostic role, and the prognosis of trophoblastic tumors after surgery can be understood by monitoring blood HCG. HCG can be examined by blood or urine, and blood HCG is more accurate and has less error compared to the traditional urine HCG, and the time of detection can be advanced, so doctors recommend HCG examination by blood. The best time for the test is 7-10 days after menstruation, and the concentration of HCG can determine whether you are pregnant or not.