A small amount of brown blood on the seventh day of menstruation may be normal menstruation, or it may be related to the presence of inflammation, endocrine dysfunction and other reasons. 1. Normal menstruation: women generally have a menstrual period of 2-8 days, and a small amount of brown blood on the 7th day of menstruation is a normal phenomenon. 2. Inflammation: If there is gynecological inflammation during the menstrual period, the inflammatory factor may affect the endometrium, which may lead to this kind of situation, including vaginitis, cervicitis, endometritis and so on. 3. Endocrine dysfunction: If there is endocrine dysfunction in the body, it will make the hormone level secretion abnormality, which will lead to abnormal bleeding of the endometrium, which may be manifested as brown secretion. The seventh day of menstruation and a small amount of brown blood may also have other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, and then give targeted treatment or treatment.