Menstruation blood: Normal charateristics of period blood

 Normal Menstruation Blood Characteristics

Menstruation blood or the menstruum(medical name) is the blood that  flows during a woman’s periods.

A few questions  often arise with regards to the menstrual blood which will briefly be addressed in this article-What is the normal color, odor, volume or consistency of menstrual blood? Should it contain blood clots? What are some common menstruall blood abnormalities?

Origin Of Menstrual  Blood

Menstrual blood originates from the normal shedding of the endometrium during normal menstruation as part of the ovulation cycle.
Though it is called vaginal bleeding, it  originates from the uterus  and not
originate from the vagina.

It simply passes through the vaginal lumen.
The term vaginal bleeding has been used medically to describe any bleeding from the female genital tract that comes out from the vagina.

Components Of Menstruation Blood

Menstrual blood is not composed of blood only. There are three qualitative components found in menstrual blood


 Blood is the main component of what is collectively called
menstruation blood or menstruum. As the endometrium breaks down, small
blood vessels leading to the endometrium are exposed and blood oozes
out. Normally these open vessels usually constrict and close. Blood is
the major quantitative component of the menstruum.


As part of normal menstruation, the endometrium is shed from the
uterus. The shed endometrium is mainly made of cells and their fibrous
support. The shed endometrium is not blood! It is hard material that may
be seen in the normal menstrual blood as tissue or clots.

Some women
have seen this tissue material during normal menstruation and report
that they probably had a miscarriage. Others have seen them it and
called them clots for they really just look like true blood
clots. The amount of shed endometrium is less than the amount of blood
in the menstruum.

The unfertilized egg

The third component in the menstruum is the unfertilized egg. It is
indeed negligible with respect to its volume when compared to the blood
or the shed endometrium. It is a single cell which cannot be seen with
the naked eye! It is however worth noting that the egg is there as part
of the flow.

Normal characteristics of Menstrual Blood

Volume of menstrual flow

average volume of menstruum is about 35 ml with a normal range of 10 to
80 ml. You need not have a measuring container to know that you are
within the normal range! Many women have learned from experience to
determine the normal volume of menstruation blood by the amount of pads
or similar menstrual product required to stay dry, and how soaked or
wet these pads are.

The color of menstrual blood

could be a wide range of normal menstruation blood color. Usually, it
is bright or light red in color, looking like the bleeding from a cut
finger especially at the onset of menstruation. It could also be brown
or almost black towards the end of menses. The reason is simple to get.
As blood stays out of the blood vessels, it begins to change its color.
The black or brown color might just be normal menstrual blood that has
changed its color as it passes through the cervix into the vagina. It is
not usually black from the blood vessels they are coming from! Note
however that persistently black menses from start to finish each month
or similar feature should not just be labeled as normal. Talk to your


It may have the normal viscosity as blood from a bleeding finger or it could be watery and thin. It may also be stringy.


menstrual blood should not be offensive in odor. Offensive vaginal
discharges may be a sign of genital infection. However, blood may
accumulate in the vagina and stink if it is left there for a long time
especially more than 6 to 8 hours. Good menstrual hygiene should salvage
such situations.

Abnormal Menstrual Blood

There are common abnormalities of menstruation blood that women often encounter.


“Blood clots during  menstruation is  frequently reported by women. Should normal menstruation blood contain blood clots? The honest answer is “no, not blood clots but a different kind of clots”.   Read more on blood clots during menstruation

Abnormal odor

Normal menstrual blood should not have an abnormal odor. The most important important cause of an abnormal odor is vaginal infection  which should prompt medical consultation. Other causes include stagnant menstrual blood, and foreign body like a forgotten tampon in the vagina.

Abnormal Color

Brown or even black menstrual blood can occur towards the end of menses because the the flow slows down and the blood spends more time in the tract and changes its color.Therefore it is a change that occurs in transit, and not from the origin.

Abnormal Volume

Heavy  and sometimes scant menstruation requires medical evaluation because there might be more serious causes and it could lead to anemia if not properly treated.  Please see Heavy Menstruation for  listing of the causes of  heavy menses

Return From Menstruation Blood To Ovulation Cycle

Return From Menstruation Blood To Menstruation Home

Comments on this entry are closed.

  • Rhirhi

    Im 16 and my blood sometimes is grey. is there something wrong ???

  • Bill Turkeyburger

    That is an incredibly delusional comment, anyone who’s been on this earth for more that two seconds can clearly see men can take pain better. It’s also been scientifically proven, for those in doubt of the obvious.

    Why do you have to go through this? Because of nature, but don’t worry, most deaths on the worksite, during physical labor, getting food, or in war have always been men. Men do the tough jobs, so this is more than fair.

    • Mallory

      Says a man who who has never experienced a single period. Let alone a couple decades of them.

      • Xasus

        Women have never been forced to go out into battlefields and slaughter complete strangers for no reason.

    • Katy

      Why on earth are you even on a site about menstruating? Just to comment that men are tougher and such…