Ever noticed that the color of your period blood changes from month to month, or even day to day? One day it’s dark red and heavy, and the next day it may be pink and light. Every woman’s period is different, and it’s normal for your period blood color to change during your cycles. This guide will answer all your questions about period blood and what it means for your health. 

Topics covered include the following: 

Let’s get started by exploring what period blood is and why it happens. 

What is period blood?

What you see on your pad or tampon is a mixture of the blood and tissue lining your uterus and is called a period. Periods are part of the menstrual cycle (1). A period is when a woman bleeds from her vagina for several days each month. Your ovaries produce an egg every month, and if the egg is not fertilized, the body sheds the lining of the uterus. The blood and tissue flow through your cervix and out through the vagina. 

Most women get their periods once every 28 days or so. However, it’s normal for some menstrual cycles to be longer or shorter. The menstrual cycle is between 21 and 40 days for many women. Your period usually lasts from three to eight days, with the heaviest bleeding in the first two days. 

Periods usually start around the age of 12, although some girls may experience their first period earlier or later. Your periods will continue until you reach menopause (2), usually when you are in your late 40s or early 50s. During the run-up to menopause, periods can often become less frequent and heavier during what’s called perimenopause. 

What are the different colors of period blood?

The color and appearance of period blood can vary from cycle to cycle. And it also changes day to day during the same period. Menstrual blood tends to be a shade or two darker than the blood you see when you cut your finger. 

The color of period blood (3) depends a lot on how long the blood stays in the uterus and vagina. Older blood tends to be darker. This is because it has had time to interact and oxidize with the oxygen in your body. 

Variations in the color and consistency of your period blood are entirely normal. However, sometimes it can be a sign of other issues and should be checked with a health professional. 

Here we explain the different colors are and what they mean for you. 

Black period blood: You may see black blood at the start or end of your period. Black period blood is usually older and has had time to oxidize, giving it a dark color. Older blood often gets released towards the end of your period from a deeper part of the uterus lining.

Brown period blood: Brown period blood can come in various shades. Brown period blood is a sign that the blood has oxidized with oxygen. You often see brown blood at the beginning or end of menstruation.

Dark red period blood: Dark red period blood is a sign of old blood. It can also come in a range of shades such as black or brown.

Bright red period blood: Bright red period blood indicates fresh blood and a steady flow. Many women see vibrant red blood during the middle of their period. However, their period blood stays a bright red color throughout. 

Pink period blood: Lighter periods are often more pink in color than red. As your period progresses, pink period blood can occur when period blood mixes with the mucus in your vagina. The natural bright red blood can become a shade of pink. 

Orange period blood: Orange period blood can also be a sign of infection. If your period blood is orange and you are experiencing other symptoms such as itching, discomfort, or an unpleasant smelling discharge, you should consult a healthcare professional. Orange period blood can happen when blood mixes with the naturally occurring fluids in the cervix. 

Grey period blood: Grey period blood or discharge can be a sign of infection. It should also be investigated by a health professional. Other symptoms include itching, painful urination, and a fishy odor. So, be sure to get a check-up if any of these apply to you.

How do consistency and flow affect period blood?

The consistency and flow of your period blood also affect the color. Your menstrual blood may be a thin and watery consistency. Or it could be thick and sticky (4). Thin and watery blood is usually seen in lighter periods and tends to be pink in color. By contrast, a thick and sticky flow occurs in heavier periods and is usually brownish. These differences are typical and reflect the tissue discharged from the uterus lining.

From time to time, your period may include clots or lumps. As your period blood naturally contains cells and tissues, this is usually nothing to worry about. However, if the clot is more than one inch in diameter, then it’s a good idea to discuss it with your health professional. 

Normal will differ from woman to woman when it comes to period blood. The amount of blood flow also varies during your period. Your period may start light before becoming heavy and then gradually trickling away. You may experience light blood flow throughout your period, or a heavy blood flow from day one may be the norm for you. 

When do I need to worry about the color of my period blood?

The most important thing is to know what’s normal for you. Keep an eye on the color and consistency of your period blood. Use an online app or simply jot down your observations in a notebook. Understanding what’s normal for you means you will quickly pick up when something is different. 

There are some potential warning signs where it’s recommended you consult with your health professional. These include the following: 

  • An unexpected change in the regularity of your periods (5) 
  • Bleeding for more than seven days or between periods
  • Pain or severe cramping during menstruation
  • Passing large clots
  • Orange or grey-colored period blood, especially if itching or an unpleasant fishy smell. 

Understanding period blood: Quick summary

Here’s a summary of period blood and what the different colors mean: 

  • The color of your period blood can change over time or even from day to day during the same period. 
  • Normal period blood ranges from black or dark brown to bright red and pink. 
  • When your period is heaviest, the blood is often bright red. On lighter days, it can be brown, pink, or black. 
  • Grey or orange-colored period blood may be a sign of infection, and it would be best to investigate further with your doctor.
  • Period blood flow and consistency vary from woman to woman. And it can also change as your period progresses. However, bleeding tends to be heaviest during the first couple of days. 
  • Monitor the color and consistency of your period blood so you get a heads up on any changes. 
  • Consult your health professional if you are worried or concerned about any differences.



  1. Your menstrual cycle, Office on Women’s Health
  2. Menopause, NHS
  3. Periods overview, HSE
  4. Heavy menstrual bleeding, CDC
  5. Irregular periods, HSE


Avril Flynn

Avril Flynn


Avril Flynn is a registered midwife and mum of one. As an expert in women’s health, Avril has been helping women gain knowledge and confidence for years. She takes a holistic approach to ensure parents feel empowered as they navigate parenthood. @AvrilTheMidwife