There are more reasons why there is blood in intercourse one or two days before and after menstruation, which may be related to physiological reasons such as changes in hormone levels, as well as pathological reasons such as cervical lesions, which need to be analyzed specifically.
1. Physiological reasons: menstrual blood is caused by the shedding of the uterine lining, one or two days before menstruation, the uterine lining has begun to shed, when having intercourse, due to the uterine contraction, there is blood. One or two days after menstruation, the uterus still has residual blood, and when you have intercourse, it stimulates the uterus and induces uterine contractions, leading to the outflow of accumulated blood and the appearance of blood.
2. Pathological reasons: if there is cervicitis, cervical polyps, cervical cancer, etc., the cervical surface of the blood vessel damage during intercourse, easy to appear vaginal blood.
The blood and other causes of intercourse a day or two before and after the onset of menstruation are also related, it is recommended to go to the hospital in a timely manner for examination, under the guidance of a professional doctor to clarify the cause of the disease, targeted treatment, so as to avoid delaying the best time for treatment.