Volume of menses

The volume of a menstrual period comprises the total amount of red cells, serum, transudate, and tissue discharged from the uterus. The menstrual volume can be quantified with research laboratory techniques, but for clinical purposes, the patient's perception of volume is of primary importance. Each of the clusters in the above panel represents a menstrual period. The first cluster would likely reflect the patient's perception of "normal" volume with a normal period length of 7 days. The second cluster reflects increased volume, primarily because of prolongation of the duration of the period: there is no increase in flow rate per day. The third cluster depicts increased volume, but with a period of normal duration with increase in daily flow rate responsible for the increased volume. The fourth cluster demonstrates a period with both increased duration and increased flow rate contributing to the increase in perceived volume.