There are some individual differences in how long it takes for HCG to fall to normal after abortion. Generally, if there is no residue in the uterine cavity, blood HCG will fall to normal in about 2-3 weeks. HCG is chorionic gonadotropin, which is a glycoprotein secreted by the trophoblast cells of the placenta. When a woman is conceived, HCG will rise significantly, and after abortion, it can gradually decline and return to the normal level. However, compared with natural abortion, the endothelial lining of the abortion falls off slower, and without any other special circumstances, it will generally fall to the normal value in about 2-3 weeks. After the abortion, we should pay attention to review the blood HCG, if it has not returned to the normal level for a long time, or if it rises again, it may be related to the incomplete abortion, and we need to carry out ultrasound examination in time, to make clear whether there is any residue in the uterine cavity.