Sunday, September 30, 2012

Red and Black

This question is from a reader. Feel free to contact me with questions!

My menstrual blood is sometimes brown instead of red. Is there something wrong with me?

No, you're fine.

Blood is bright red when it is oxygenated. Blood has hemoglobin, which can bind oxygen molecules. In the lungs, oxygen is passed from the lungs into the blood, turning it bright red. As the blood is transported through the body, its oxygen is transferred to the organs it passes through, and the blood becomes darker (dark red, bluish). By the time it reaches the veins (which bring blood back to the heart), much of the oxygen content has reduced.

During menstruation, blood is shed by the lining of the uterus, and that is usually bright red blood. The blood does not always come out immediately. It can sit in the uterus, cervix or vagina for some time before the woman sees the blood. In that time, the blood can be oxidized (which is different from oxygenated) - it involves a transfer of electrons, rather than just binding of oxygen to hemoglobin. When blood is oxidized, it turns brownish or black.

Therefore, brownish period blood is merely blood that has been sitting around for a while. All blood, after being exposed to air, will eventually turn brown or black.

(Incidentally, this is why stool can sometimes be black - because there is gastrointestinal bleeding. If you have black stools, see your doctor)


Voice said...

Hi Dr Ades,

My name is Aliaha Daphnis. I'm currently a highschool Senior and I am absolutely fascinated with your profession. I aspire to be a Ob/Gyn as well. Im currently receiving my A.A. degree in Chemistry but, I plan to receive my Bachelor's in International Relations (fulfilling Medical School requirements)and hope to earn my M.D. and eventually work for MSF. I would really like your advice on the process of becoming a med-student, residency and also how you became apart of MSF. It would be gratefully appreciated. Thank you.

(You're such an inspiration)

Anonymous said...

Hi Veronica -
Your work on the MSF blog and Wanderlust are absolutely great! For a new nonfiction anthology, The Places We’ve Been: Field Reports from Travelers Under 35, we are currently looking for submissions and would love to invite you to take a look and consider if you might like to participate. A bit of info from the general call for submissions is available at The posted deadline is stated as October 15 - but we have a special invitation/extension through November 15 for invited bloggers.

Thanks for your consideration, and feel free to be in touch for more information or questions!
editor [at] theplaces35 [dot] com