The main reasons why a low placenta may bleed are as follows: First, the placenta is located relatively down, close to the cervical opening, if the activity is relatively large or the sexual life is too intense, it will produce direct stimulation to the body and thus the symptoms of bleeding. Secondly, the symptoms of bleeding may be due to a partial abruption of the placenta and the uterine wall, which is relatively large and may be dangerous. It is recommended that pregnant women should pay special attention to these problems during pregnancy, and if it is placenta praevia, it is best to pay attention to conditioning the body, rest more and not to carry out strenuous exercise, not to lift heavy objects and frequent sedentary, long standing, so as not to cause dangerous problems, which may affect the growth and development of the fetus.