Period blood can be pink, bright red, dark red, brown or almost black. These changes are often linked to blood flow and how long blood takes to leave the body.
Colour alone rarely tells you whether something is wrong. How much you bleed, when bleeding occurs, pain and changes from your usual pattern are usually more useful clues.
On this page
- Why does period blood change colour?
- Period blood colours and what they may mean
- What about period blood clots?
- When is a change in bleeding worth checking?
- What is more useful to track than colour?
- The main takeaway
Why does period blood change colour?
Menstrual fluid contains blood and tissue shed from the lining of the uterus, along with cervical mucus and vaginal fluid.
Its appearance can change depending on your flow, how long blood takes to leave the body and whether it mixes with other fluid.
Blood that leaves the body relatively quickly often looks brighter red. Blood that takes longer to leave the uterus or vagina reacts with oxygen and becomes darker, which can make it appear dark red, brown or almost black.
There isn't one colour your period needs to be. Pink, red and brown shades can all occur during an ordinary period.
Period blood colours and what they may mean
Period blood can naturally appear in different shades. Colour alone isn't a reliable way to diagnose a health condition.
Bright red
Bright red blood is common when menstrual blood is leaving the body relatively quickly.
You may notice it on heavier-flow days, although bright red blood can occur at any point during a period. It can also appear with spotting or bleeding outside your expected period.
Dark red
Dark red blood may simply have taken a little longer to leave the uterus or vagina.
It can also be more noticeable during heavier bleeding or alongside menstrual clots.
Pink
Pink bleeding often happens when a relatively small amount of blood mixes with vaginal discharge or cervical mucus.
You might notice it with light bleeding, spotting or at the beginning or end of a period.
Pink blood by itself doesn't tell you that your oestrogen is low or that there is a hormonal problem.
Brown
Brown blood is very common, especially when menstrual flow is slowing down.
It usually means the blood has taken longer to leave the body and has darkened through oxidation.
You may notice brown blood at the beginning or end of your period or as light spotting after the heavier part of your period has finished.
Almost black
Very dark brown or dark red menstrual blood can sometimes look almost black.
On its own, this often reflects blood that has taken longer to leave the body rather than something being wrong.
If very dark bleeding is new for you and occurs with pelvic pain, fever, an unpleasant smell, unusual discharge or other symptoms, see a healthcare professional rather than trying to work out the cause from colour alone.
These colour patterns are useful observations, not a diagnostic chart.
If you're bleeding outside your expected period, read our guide to spotting and bleeding between periods.
What about period blood clots?
Small blood clots can occur during a period, particularly on heavier-flow days.
When bleeding is heavier, blood may collect and clot before it leaves the uterus. This can create dark red or jelly-like clots in menstrual fluid.
The occasional small clot doesn't necessarily mean something is wrong.
Passing clots larger than a 50 cent coin is one of the signs healthdirect lists for heavy menstrual bleeding.
See a doctor if you're regularly passing large clots, the size or number of your clots has changed or they occur with very heavy bleeding, significant pain, dizziness or other new symptoms.
Clot size and the overall pattern of your bleeding usually tell you more than the colour of the clot itself.
Read more about how much you bleed during your period.
When is a change in bleeding worth checking?
It's worth speaking with a GP or another qualified healthcare professional if you experience:
- periods lasting longer than 8 days
- needing to change a pad or tampon every 1 to 2 hours
- regularly needing to change period products overnight
- clots larger than a 50 cent coin
- bleeding through clothing or bedding
- bleeding that interferes with work, study, exercise, sleep or other normal activities
- bleeding between periods
- bleeding during or after sex
- any vaginal bleeding after menopause
- significant pelvic pain
- fever or unusual vaginal discharge alongside bleeding
Menstrual cups and discs hold different amounts, so there isn't one number of times you should need to empty every product.
If you suddenly need to empty your cup or disc much more frequently than is normal for you, tell your doctor which product you're using and how often you're emptying it.
If you're not sure how to explain what you've noticed, our guide to talking to a doctor about vaginal concerns may help.
What if the colour change is actually discharge?
Green, yellow, grey or frothy discharge or discharge with a fishy or unpleasant smell is different from normal variation in menstrual blood colour.
Changes like these can occur with vaginal infections, including bacterial vaginosis, thrush or some sexually transmitted infections, and are better assessed as a discharge concern rather than interpreted using a period blood colour chart.
Read our guide to vaginal discharge for more information.
What if you think you've forgotten a tampon?
A retained tampon can cause unusual discharge, an unpleasant smell, itching, redness or pelvic discomfort.
If you think a tampon has been left in, remove it as soon as you can. If you can't remove it easily yourself, see a doctor rather than using another object to try to retrieve it.
Seek urgent medical care if a retained tampon is accompanied by symptoms such as fever, rash, dizziness, confusion, difficulty breathing, muscle aches or diarrhoea.
When is heavy bleeding urgent?
Seek urgent care if your bleeding is suddenly much heavier than usual or heavy bleeding is accompanied by dizziness or weakness.
Call triple zero (000) if you're bleeding very heavily and feel faint, think you may pass out or feel seriously unwell.
What if pregnancy is possible?
If you are pregnant or could be pregnant and experience bleeding or spotting, contact a doctor, midwife or other pregnancy care provider promptly.
Bleeding during pregnancy has many possible causes and doesn't automatically mean something is seriously wrong, but it should be assessed.
Go to an emergency department or call triple zero (000) if bleeding during pregnancy occurs with severe abdominal or pelvic pain, back pain, shoulder-tip pain, dizziness, fainting or heavy bleeding. These can be symptoms of an ectopic pregnancy, which requires urgent medical care.
What is more useful to track than colour?
If you want to understand your menstrual pattern, there are several things that are generally more useful than trying to interpret every shade of blood.
You might record:
- the first and last day of your period
- whether your flow feels light, moderate or heavy
- how frequently you need to change or empty period products
- whether you experience flooding or leaks
- the size and frequency of blood clots
- pain or cramping
- bleeding between periods or after sex
- tiredness, dizziness or shortness of breath
- whether your period interferes with everyday activities
You can record colour too if you find it useful, but you don't need to check or categorise every shade.
Menstrual cups and menstrual discs can make blood colour and clots more noticeable because menstrual fluid is collected rather than absorbed.
That can help you become familiar with your own pattern, but what you see in a cup or disc doesn't diagnose a health condition.
Our free downloadable period tracker can help you record your cycle and symptoms before an appointment.
You can also explore our Period Care and Pelvic Health Guides for more practical information.
The main takeaway
Pink, bright red, dark red and brown menstrual blood can all occur during an ordinary period. Very dark red or brown blood can also look almost black.
In most cases, colour tells you more about the speed of your flow and how long the blood has taken to leave your body than it does about your health.
Pay more attention to how much you're bleeding, when bleeding occurs, whether you're passing large clots, pain and changes from your usual pattern.
If something has changed or your bleeding is affecting your life, a GP can help investigate what's happening.
Explore our free period trackers if you'd like an easy way to record useful details.
Related reading
- How much do you bleed during your period?
- What is spotting? Bleeding between periods explained
- Vaginal discharge: what's normal and when to get checked
- Everything you need to know about getting your period
Sources and further reading
- healthdirect: Heavy periods
- healthdirect: Vaginal bleeding
- healthdirect: Bleeding between periods
- healthdirect: Ectopic pregnancy
- healthdirect: Vaginal discharge
- healthdirect: Retained tampon or other object
- Cleveland Clinic: Period blood colour
This article provides general health information and isn't a substitute for individual medical advice.