What does the colour of blood in your period mean?
In this article
What's the lowdown?
Period blood is not always red in colour
It reacts with oxygen the longer it is exposed to air and darkens over time
Dark red, brown and black are normal colours to see during your period
Colour of blood in periods
Have you ever sat there analysing your period colour? Red, orange, maybe even green …..
What colour of the rainbow is it now?!
Our period is our body’s way of getting rid of the thickened womb lining that isn’t needed if the egg you released that month isn’t fertilised. It leaves our womb through our cervix, down our vaginal canal and out the vagina1.Â
Period blood acts in the same way as all blood. Fresh blood starts bright red, and once in contact with oxygen in the air, a reaction called oxidation occurs which slowly deepens the blood’s colour.
The colour of your period blood is a good indicator of your gynaecological health. Don’t dismiss what the colours mean, it might be your body’s way of telling you something is up!
Bright red period blood
At the start of our period, your blood will look bright red. That is the colour of fresh blood. As this is the initial blood leaving your body, it does not have time to react with oxygen so will look very bright. This is normal for most of us, but can be associated with conditions that cause heavy periods like endometriosis, adenomyosis or fibroids.
Dark red period blood
As your period progresses, it has more time to oxidise and slowly darken in colour as the flow of blood out of your body slows down. This might be the appearance of your blood a few days into your menstrual flow. Not a cause for worry!
Brown and dark brown period blood
Oh goodness, why is my period blood brown now?
This can be quite common near the end of your cycle. As the last bit of your lining has been sitting in your uterus for some time, it had ample time to mix with oxygen and develop a brown or dark brown colour. But brown is still a normal variant of period blood colour.
Sometimes you might see specks of brown period blood or dark brown period blood at the start of your cycle. This could be due to remnants of your previous menstrual cycle.
Black period blood
Black period blood is the blood that has overstayed its welcome. The old womb lining has had too much time sitting around, reacting with oxygen before finally making its way out of our body.
Seeing black in your underwear can be as normal as seeing red, however, if you have black blood at the start of your period alongside symptoms of very painful periods, it can be a sign of endometriosis.
Pink period blood
Pink period blood could be a little clue that your period is creeping up on you. Time to keep those period products in arms reach!
Small amounts of period blood can mix with your vaginal discharge2, leaving a pink hue on your undies. This is medically called spotting.
At other times, seeing some pink could be a sign of:
- Vaginal dryness
- Bacterial vaginosis (BV)
- Sexually transmitted infections (STI)
- Cervical cancer
- Endometrial cancer
If this pink period blood or spotting is happening after sex or inbetween your normal periods, it is best to see a healthcare professional and get things checked to rule out any worrying causes of bleeding!
Orange period blood
Orange is a tricky colour. It could be a red hue but the light makes it look orange. Or it could be an STI3.Â
Does the orange smell weird, it is frothy? These are all signs of an infection.
It is important to get an STI checked. If left untreated, it can lead to pelvic inflammatory disease4 which may have fertility and menstrual complications in the future.Â
Green period blood
Green is definitely not a period colour. It is usually a sign of infection such as bacterial vaginosis or trichomoniasis5.Â
You might notice a foul-smell, vaginal soreness/itching or fevers.
This is definitely one to look out for.
Blood clots in periods
Blood clots are a normal albeit scary finding during your period! They can vary in size from small, medium to large. Clots are more common during the first few days of your period, the heaviest flow days! If you never have a clotty period, that’s nothing to stress about either.
Clots are only considered a worrying period symptom when they are larger than 2.5cm or for reference, a 10p coin6.
We cover more on the types of clots you might find attached to your pad or clinging to your menstrual cup here!
Bleeding between my periods
Again, more blood!
Bleeding between your periods or spotting can simply be a natural occurrence such as ovulation or due to medications such as contraceptives. There are many causes and it’s not always a cause for concern7, however, if it continues for 3 cycles, you should see a doctor for a check up.
To learn more about spotting between periods, we break down this topic into the various causes and when to get things checked here.Â
What now?
The ideal colour scheme of your period should be bright red, dark red, brown, dark brown or black.
We recommend seeing a doctor for period blood that does not fit this colour palette. Do not put this off. Your body is trying to tell you something is not quite right. If you don’t listen to it, who will?
Our Lowdown GPs will that’s for sure! Your health is very important to us. If you are concerned about anything, no worry is too big or small.
Reach out to our medical team, we are here to advise you on everything women’s health.
Dr Fatema Dawoodbhoy
Fatema is currently training in London as an Academic doctor, with a special interest in Obstetrics and Gynaecology. She is passionate about championing women to understand their bodies better and prioritise their health. She understands the importance of clinically accurate articles and has been writing engaging and educative medical content for 5 years.
Our medical review process
This article has been medically reviewed for factual and up to date information by a Lowdown doctor.
