Wellness·5 min read

What Your Period Blood Color Can Tell You About Your Cycle (And Health)

A woman sitting on the toilet with a pad in her underwear
Design: theSkimm | Photo: iStock
November 9, 2022

POV: You're on your period. You're swapping out your period product of choice when you look down and wonder, 'Wait, why is my period blood brown?' Or pink. Or black. Or any other color you might not have expected to see. 

As it turns out, your period blood color can tell you a surprising amount about your cycle and your health overall. So we asked Dr. Allegra Cummings, OB-GYN at Weill Cornell Medicine, to talk us through what each color means, and when to see your doctor.

A chart of the different colors and consistencies of period blood.
Design: theSkimm

What does each period blood color (or consistency) mean?

Dark red or brown period blood

Good news: Dark red or brown period blood is typically nothing to be concerned about. “The primary reason that period blood could be brown is because it's old blood,” said Dr. Cummings. 

It usually happens at the beginning or the end of your period, when your flow is lighter. Because the longer blood takes to leave the body, the longer it has to oxidize (read: get exposed to oxygen), which makes it dark. “It's not necessarily a bad thing at all,” said Dr. Cummings. “It often just means that it's a lighter bleeding and so it's just coming out slower.” 

Another reason for dark red or brown period blood: Birth control. It can reduce how much you bleed overall, said Dr. Cummings, and when there’s not very much blood, it can take longer to come out. 

And something that might lead to brown blood in your underwear, but actually isn’t your period: implantation bleeding. Aka, the normal spotting that happens about two weeks into pregnancy.

Pink period blood

Pink period blood can show up at the start of your period. And is typically that color because the blood has mixed with vaginal discharge. (Which is typically nothing to be concerned about.) It can also show up if you’re on birth control, because that can lower your estrogen levels and cause a pink hue during periods.

Note: If you’re experiencing blood in discharge but you’re not on your period, it may be from small tears in the vagina after sex. Or, it could be normal spotting during ovulation.

Bright red period blood

Bright red blood usually hasn’t had much time to oxidize. It often happens during a steady flow. “When people are having heavier periods, that's typically when you'll get that bright red blood,” said Dr. Cummings. 

Black period blood

Black blood is even older than dark red or brown period blood. But if you experience black period blood along with some pregnancy symptoms, and it doesn’t turn into a period (read: it only lasts one to three days), it may actually be implantation bleeding. Or, it could be a sign of a miscarriage. Yes, the human body can be confusing. Check with your doctor if something feels off or if you have questions. 

Orange period blood

If you’re seeing blood with an orange hue, Dr. Cummings explained that it might not just be period blood. Meaning, it could be blood mixed with vaginal discharge that’s caused by an underlying infection. Like bacterial vaginosis  (aka BV), which is inflammation caused by an imbalance of bacteria, or trichomoniasis (an STD). If this happens to you, call up your doc to get more info.

Gray period blood

Another case of vaginal discharge mixed with period blood. Gray discharge can be a sign of BV. Which may come with other symptoms like itching and a fishy smell. Also another case where you should reach out to your doctor.

Green period blood

It may be a sign of an infection like trichomoniasis or BV. Again, reach out to your doctor if you notice green in your period blood. 

Jelly-like blood clots

Don’t be alarmed by “jelly-like” bright or dark red period blood clots. Because they’re usually normal collections of blood cells and tissue. But if you notice blood clots bigger than the size of a quarter during your period (more on that below), check with your doctor. Speaking of which…

What are signs you’re losing too much blood during your period?

Losing two to three tablespoons of blood during your period is considered normal. And that’s usually across four to five days (although it may vary slightly for different people). But if you experience excessive bleeding, it may be a sign of menorrhagia — heavy or prolonged bleeding that could cause anemia. So you might want to see a doctor if…

  • You see blood clots that are bigger than the size of a quarter

  • Your period lasts longer than seven days

  • You have to change your tampon, pad, or cup frequently (think: every hour for several hours)

  • You feel weak or sluggish during your period

  • Your period is getting in the way of regular life 


Period blood, just like vaginal discharge, can come in different colors and textures. Which can be alarming if you don’t know what they mean. But it’s often your body’s way of telling you where you are in your cycle, and when to see a doctor. 

This content is for informational and educational purposes only. It does not constitute a medical opinion, medical advice, or diagnosis or treatment of any particular condition. 

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