Starting from puberty, girls begin to experience a monthly flow which we commonly refer to as a period. You may notice the color of your period blood varies. Sometimes it’s a bit brown, or almost black, to later turn to bright crimson. It can sometimes be alarming to look down and see some dark brown to black looking discharge but the good news is that such variations do not mean anything sinister. So, why the different shades?
Blood (and tissue) changes color depending on how long it has been exposed to air oxygenation. Think of when you cut your skin—red blood comes out of a fresh wound. If you put a bandage on it and check it the next day, you’ll see that once-red blood will have turned brown. Blood color appears darker because it has reacted with oxygen, and the majority of the water in blood will have evaporated, making it more concentrated and darker.
Your endometrium is the inner lining of your uterus, which is where a fertilized egg would implant and grow. The endometrium is made up of highly vascularized tissue with special spiralized arteries. This provides a fertilized egg with easy access to a fresh blood supply (carrying nutrients and oxygen), so it can start to develop.
When you get your period, these specialized spiral arteries constrict, and actually limit blood flow loss . So, even though it may look like fresh red wound blood is pouring out of your vagina, rest assured, there is no wound that you are bleeding from. Your endometrium does not separate all at once, it’s a slow, controlled separation, and it takes time for your endometrial tissue to make its way down through your cervix and vagina.
Black period color
You may be alarmed to see black blood, but it isn’t necessarily a reason to worry. This color is related to brown blood, which is old blood. It may resemble coffee grounds. Black blood is usually blood that’s taking some extra time to leave the uterus.
Brown/dark red period color
At the beginning or end of your period, blood can be a dark brown/red shade and can have a thick consistency—but it’s also normal for the first signs of your period to be bright red and more fluid-y. If your period blood appears brownish at the start or end, it’s because the blood is older and took longer to leave your uterus. The uterine lining darkens the longer it takes to leave the body. Period blood clots are normal on the heaviest days of your period and can appear deep red or almost dark black as well.
Missed miscarriage
Although miscarriage may be associated with bright red bleeding, some women may experience what’s called a “missed miscarriage.” With this type of pregnancy loss, the fetus stops developing but doesn’t pass from the uterus for at least 4 weeks. You may not experience heavy bleeding or clots, but some women do develop dark brown spotting or bleeding.
Bright red period color
Your period may start with bright red bleeding. This means that the blood is fresh and is flowing quickly. Your blood may stay this way your whole period or may darken as your flow slows.
Period flow typically becomes heavier on the second or third day of the cycle as the uterine lining sheds faster. Bright red period blood is newer blood, thus it doesn’t have time to darken before it exits your body.
Pink
For many women, light pink bleeding is how their period starts. Some may have this for the first day of their period. Spotting is any bleeding that happens outside of your regular period. Some people experience spotting mid-cycle, also known as ovulation bleeding.
Low hormone levels: Sometimes pink menstrual blood may indicate low estrogen levels in the body. Estrogen helps to stabilize the uterine lining. Without this hormone, you may shed the lining at times throughout your cycle — leading to spotting of various colors, including pink. Some causes of low estrogen include being on a hormonal birth control that doesn’t contain estrogen, or perimenopause.
Implantation spotting
Some women have light pink spotting around the time of suspected implantation or 10 to 14 days after conception. Not all women experience implantation spotting, but it can range in color. If you have spotting that doesn’t turn into a period, it’s a good idea to take a pregnancy test (especially if you’ve been having unprotected sex)
It is normal for the color to be different at the beginning and end of your period
Your period may change colors from the beginning to the middle to the end. You may even have different colors from month to month or at different times throughout your life. There are a number of factors involved, even when your periods are totally “healthy.”
As explained earlier, the variation from bright red to dark red to brown has something to do with the flow and time the blood has been in the uterus. Your flow may be faster at the beginning of your period and trail off toward the end. You may have dark red blood after laying down for a long time, too. You may see bright red blood on your heaviest days.
A range in period blood color is normal, and doesn’t signify anything serious.
But do pay attention to your flow volume, changes in cycle length, and pain, as these are more likely to indicate any problems.
