# How much blood volume does the average woman lose over the course of her period? **URL:** \ **Category:** Factual Questions\ **Created:** [October 20, 2002, 12:58am UTC](https://boards.straightdope.com/t/how-much-blood-volume-does-the-average-woman-lose-over-the-course-of-her-period/133032 "2002-10-20T00:58:19Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [October 20, 2002, 12:58am UTC](https://boards.straightdope.com/t/how-much-blood-volume-does-the-average-woman-lose-over-the-course-of-her-period/133032/1 "2002-10-20T00:58:19Z")
Just curious. ---
**Author:** ![Baraqiyal](https://avatars.discourse-cdn.com/v4/letter/b/ecccb3/32.png) [@Baraqiyal](https://boards.straightdope.com/u/Baraqiyal)\ **Post date:** [October 20, 2002, 1:47am UTC](https://boards.straightdope.com/t/how-much-blood-volume-does-the-average-woman-lose-over-the-course-of-her-period/133032/2 "2002-10-20T01:47:11Z")
I remember from listening to the Dr. Edell show that it’s less than most women think. He said it was about 8 teaspoons. ---
**Author:** ![Eva\_Luna](https://avatars.discourse-cdn.com/v4/letter/e/e495f1/32.png) [@Eva\_Luna](https://boards.straightdope.com/u/Eva_Luna)\ **Post date:** [October 20, 2002, 2:38am UTC](https://boards.straightdope.com/t/how-much-blood-volume-does-the-average-woman-lose-over-the-course-of-her-period/133032/3 "2002-10-20T02:38:14Z")
I seem to remember about the same (a few teaspoons) from high school bio. It just looks like more because it’s combined with other stuff (endometrium, mucous, etc.) ---
**Author:** ![Nametag](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/nametag/32/406_2.png) [@Nametag](https://boards.straightdope.com/u/Nametag)\ **Post date:** [October 20, 2002, 2:41am UTC](https://boards.straightdope.com/t/how-much-blood-volume-does-the-average-woman-lose-over-the-course-of-her-period/133032/4 "2002-10-20T02:41:35Z")
It’s my understanding that no blood volume is lost; menstrual fluid is composed of blood and other tissue that’s been deposited over the course of the previous weeks, and in a healthy woman there is no blood lost from the circulatory system. But that’s just what I understood. ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [October 20, 2002, 3:04am UTC](https://boards.straightdope.com/t/how-much-blood-volume-does-the-average-woman-lose-over-the-course-of-her-period/133032/5 "2002-10-20T03:04:26Z")
Fluid lost during menses normally ranges from 3 tsp to a cup, depending on the individual. As for the composition of said fluid, > [@](#): > > The percentage contribution of blood (equivalent to mixed venous blood from the cubital fossa) to the total varied very greatly from woman to woman (1.6 to 81.7%) with a mean of 36.1 +/- 3.6%. The proportion of blood remained approximately the same for different total volumes and on different days of the cycle. Women using no contraception or who had undergone tubal sterilization had similar ratios of blood to total fluid loss, whereas intrauterine device (IUD) users had a higher ratio and oral contraceptive users a lower ratio that just reached statistical significance. It seems probable that the major component of the fluid loss that cannot be accounted for by blood is from endometrial tissue fluid rather than vaginal or cervical secretions. [http://www.2womenshealth.co.uk/24-02-878.htm](http://www.2womenshealth.co.uk/24-02-878.htm) ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [October 20, 2002, 3:25am UTC](https://boards.straightdope.com/t/how-much-blood-volume-does-the-average-woman-lose-over-the-course-of-her-period/133032/6 "2002-10-20T03:25:03Z")
> [@](#): > > \*Originally posted by Nametag \* > \*\*It’s my understanding that no blood volume is lost; menstrual fluid is composed of blood and other tissue that’s been deposited over the course of the previous weeks, and in a healthy woman there is no blood lost from the circulatory system. > > But that’s just what I understood. \*\* So heavy periods would not be responsible for anemia in an otherwise healthy woman? ---
**Author:** ![amarinth](https://avatars.discourse-cdn.com/v4/letter/a/3be4f8/32.png) [@amarinth](https://boards.straightdope.com/u/amarinth)\ **Post date:** [October 20, 2002, 4:13am UTC](https://boards.straightdope.com/t/how-much-blood-volume-does-the-average-woman-lose-over-the-course-of-her-period/133032/7 "2002-10-20T04:13:12Z")
I’ve heard it can contribute. I’ve had doctors always check to see when my last cycle was when they check my iron levels, and I have to ensure I’m at the right time of month before I donate blood, otherwise I’m too low on iron. However, that’s less than scientific. However, [this site](http://www.personalmd.com/news/anemia_1108000.shtml) says that menstruation is the main cause of iron deficiency anemia. ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [October 20, 2002, 4:25am UTC](https://boards.straightdope.com/t/how-much-blood-volume-does-the-average-woman-lose-over-the-course-of-her-period/133032/8 "2002-10-20T04:25:11Z")
> [@](#): > > \*Originally posted by astro \* > \*\* > > So heavy periods would not be responsible for anemia in an otherwise healthy woman? \*\* Menses are by far the most common cause of anemia in women! As was stated in my post, menstrual fluid averages about 36% blood.