What Causes Menstrual Blood to Clot?
The Merck Manual states that during a normal menstrual period, women bleed between three to seven days. During this time, the blood flow can be light, medium or heavy and may be accompanied by blood clots. Although the majority of women who complain of blood clots have heavy menstrual cycles, blood clots can occur even in women with light cycles. In a normal menstrual flow, the body releases anticoagulants to keep the blood from clotting. However, if the blood flow is extremely heavy or strong, the body doesn’t have enough time to send out these anticoagulants, so the blood clots. Passing blood clots the size of a quarter or larger is not normal.
