Updated: Oct 29, 2020
Oh yay, periods. We all know the annoyance of the flow and the panic of blood seeping through (but you can help put that fear to rest with leak-proof period underwear from Ruby Love to guard the flow) – but just what is that menstrual flow made up of anyway? With the average woman menstruating for over 40 years of her life (and with a mean of 13 periods a year) that’s a lot of blood and stuff you will be losing, so why not get to know a little more about just what it all is?
It’s Not Just Blood
While we often refer to it as “bleeding” or “period blood” the truth is that it is actually more than just blood – and made up of probably less actual blood than you may expect. Our monthly cycle prepares our uterus for pregnancy. To do this, the uterine lining thickens and blood flow increases. If the egg that is released does not get fertilized, then, the uterus most return to its normal state, and that means dumping the extra blood, tissue, etc.
How Does It Differ From Regular Blood?
What we think of as strictly “menstrual blood” is, rather, a mix of blood itself, cells from the mucous lining from the vagina, old uterine tissue that has been shed and bacteria that is found in the vaginal flora.
Because of this composition, menstrual blood is not exactly normal blood, but rather blood mixed with secretions, tissue and mucus. The exact composition, makeup, and percentage of each component does, of course, differ from woman to woman, as well as depend on factors such as age, medical history, the thickness of the uterus – even what stage of menstruation a person is on.
Any vaginal secretions that come out with menstrual blood typically are mostly water and electrolytes like sodium and potassium. And, when compared to normal blood, the concentrations of proteins, bilirubin and cholesterol are much lower – in fact, most usual blood-associated substances are less present, aside from water. Iron, hemoglobin, etc. are all much more present in ordinary blood.
What Else Is Not Present in Menstrual Blood
While there are many substances found less in menstrual blood, there are some missing substances that are nowhere to be found for a very important reason – substances that are normally necessary for the flow to coagulate properly. The body wants this mixture of substances to remain liquid and not thicken or harden, both inside and outside of the body. Menstrual blood is not meant to be able to gel up or scab over, whether it remains internal or once you have passed it.
The three elements that normal blood has for coagulation, prothrombin, thrombin and fibrinogen are not present in menstrual blood. Instead, it adds elements to keep it thin. Also, there are less blood platelets than in normal blood, to help keep the flow waterier and more unable to be fully congealed.