The common reasons for the presence of brown blood in the week before menstruation are as follows:

1, women of childbearing age: have normal sex, first of all, to determine whether pregnancy, can be detected at home using early pregnancy test paper. If there is pregnancy, you should go to the hospital in time, and further treatment;

2, gynecological inflammation: may cause the presence of a small amount of blood in the week before menstruation, you can go to the hospital after menstruation is clean to carry out leukorrhea examination, or check the blood related indicators;

3, luteal insufficiency: because the week before menstruation happens to be the luteal phase, the luteal phase is the latter part of the menstrual cycle, the formation of ovulation after the the corpus luteum, which maintains female hormone levels. If that function is insufficient, endothelial instability can also cause bloodstains to appear.

Expanded

1, in the week before menstruation, if there is brown blood, it may be due to ovulation bleeding, from the modern medical aspect of the disease is caused by the lack of estrogen levels, ovulation bleeding is also known as the middle of the menstrual period bleeding, or known as the menstrual bleeding, actually refers to two times the normal amount of bleeding, but also the time between the menstruation of the blood, the blood of the menstrual cycle, the blood of the women's body is not enough. It is also known as mid-menstrual bleeding or inter-menstrual bleeding, which is a small amount of bleeding that occurs between two normal menstrual periods, and may be accompanied by varying degrees of pain in the lower abdomen.

2, in addition to ovulation bleeding, in the menstrual period before the brown discharge may be non-physiological situation, in the menstrual period before the brown discharge, is caused by organic lesions or drugs and other factors, such as genital inflammation, endocrine disorders or tumors, and abnormal development, as well as nutritional deficiencies and other factors.