Why Is My Period Blood Dark Brown?

Many women experience changes in the color and consistency of their period blood throughout their menstrual cycle. While it is common for period blood to be bright red or a lighter shade of red, it is also normal for it to be dark brown at times. In most cases, dark brown period blood is simply old blood that has taken longer to leave the uterus.

When your period begins, the lining of your uterus sheds and is expelled through the vagina. The color of the blood can vary depending on how quickly it is expelled. If the blood takes longer to leave your body, it can mix with cervical mucus and other vaginal secretions, causing it to appear dark brown.

Another reason for dark brown period blood could be the presence of a small amount of endometrial tissue. This tissue is shed during your period and is responsible for the uterine lining thickening and shedding each month. When this tissue mixes with blood, it can contribute to the dark brown color.

It is important to note that while dark brown period blood is usually nothing to be concerned about, there are instances where it may indicate an underlying condition. If you experience consistent dark brown period blood accompanied by severe pain, abnormal bleeding patterns, or other concerning symptoms, it is recommended to consult with a healthcare provider to rule out any potential health issues.

Normal Menstrual Blood

Normal menstrual blood can vary in color and consistency, but it is typically bright red in the beginning of the period and becomes darker as the days go by. The color can range from light pink to dark brown, depending on factors such as the flow rate and the time it takes for the blood to exit the body.

The texture of normal menstrual blood can also vary. It is usually thinner and more watery at the beginning of the period, and becomes thicker and more clotted towards the end. This is because the blood has had more time to coagulate as it exits the body.

During menstruation, the uterus sheds its lining, which is made up of tissue and blood. This shedding is necessary for the body to prepare for a potential pregnancy. The amount of blood lost during a menstrual period can vary, but on average, it is about 30-40 milliliters, or around two to three tablespoons.

See also  Urobilinogen, Ua

If you notice any significant changes in your menstrual blood, such as a sudden increase in flow, prolonged periods of heavy bleeding, or the presence of large blood clots, it is important to consult with a healthcare professional. These could be signs of an underlying health condition that may need to be addressed.

In summary:

  • Normal menstrual blood can vary in color from bright red to dark brown.
  • It can also vary in texture, becoming thicker and more clotted towards the end of the period.
  • The average amount of blood lost during a menstrual period is about 30-40 milliliters.
  • If you notice any significant changes in your menstrual blood, it is important to seek medical advice.

Causes of Dark Brown Period Blood

Dark brown period blood can be caused by a variety of factors, including hormonal changes, uterine lining buildup, and the presence of old blood in the uterus.

Hormonal Changes:

Fluctuations in hormone levels during the menstrual cycle can affect the color of period blood. When estrogen levels are high, the blood tends to be bright red. However, when progesterone levels increase, the blood may appear darker, ranging from a deep red to brown.

Uterine Lining Buildup:

If the uterine lining does not shed completely during the previous period, it may build up and continue to shed during the current menstrual cycle. This can result in dark brown period blood, as the older blood has had more time to oxidize and darken.

Presence of Old Blood:

Dark brown period blood can also be caused by the presence of old blood in the uterus. This can occur if the flow of menstrual blood is slow or if the blood has been stagnant in the uterus for some time before being expelled. As a result, the blood may appear darker in color.

If you are experiencing consistently dark brown period blood or have concerns about your menstrual cycle, it is important to consult with a healthcare professional for further evaluation and guidance.

Potential Health Concerns

Dark brown period blood can sometimes indicate potential health concerns and should not be ignored. While it is typically normal for period blood to vary in color and consistency throughout your menstrual cycle, there are a few health conditions that can cause your period blood to appear dark brown.

Endometriosis: Endometriosis is a condition in which the tissue that normally lines the uterus grows outside of it, often causing pain and fertility problems. Dark brown period blood can be a symptom of endometriosis, as the tissue that sheds during menstruation may mix with other fluids and become discolored.

See also  Belly Button Pain When Pressed

Polycystic ovary syndrome (PCOS): PCOS is a hormonal disorder that can cause multiple cysts to develop on the ovaries. Women with PCOS may experience irregular periods or prolonged periods, leading to the accumulation of older blood in the uterus. This can result in dark brown period blood.

Uterine fibroids: Uterine fibroids are noncancerous growths that can develop in or around the uterus. They can cause heavy or prolonged periods, which can lead to the appearance of dark brown period blood.

Sexually transmitted infections (STIs): Certain STIs, such as chlamydia or gonorrhea, can cause changes in the color and odor of your menstrual blood. If you suspect you may have contracted an STI, it is important to seek medical attention.

If you consistently experience dark brown period blood or have any other concerning symptoms, it is recommended to consult with a healthcare professional for a proper diagnosis and appropriate treatment. Ignoring potential health concerns can lead to further complications, so it is important to address any abnormal changes in your menstrual cycle.

When to See a Doctor

If you notice that your period blood is consistently dark brown and you are experiencing other concerning symptoms, it may be a good idea to schedule an appointment with your gynecologist. While dark brown period blood is generally nothing to be alarmed about, there are instances where it could indicate an underlying issue.

One reason to see a doctor is if you are also experiencing severe pain or cramping during your period. Dark brown period blood accompanied by intense pain could be a sign of a condition such as endometriosis or fibroids, which may require medical attention.

Additionally, if you are experiencing unusually heavy periods with dark brown blood, it could be a sign of anemia. Anemia occurs when your body doesn’t have enough red blood cells to carry oxygen to your tissues, and it can be caused by a variety of factors. A doctor can help diagnose and treat the underlying cause of your heavy and dark brown period blood.

Finally, if you have recently started or changed any medications, it may be worth speaking to your doctor about your dark brown period blood. Certain medications, such as hormonal contraceptives, can affect the color and consistency of your menstrual blood. Your doctor can provide guidance on whether the medication could be causing the change and recommend any necessary adjustments.

About Us

Family Medicine

Family MedicineIn 2024 our team of doctors and nurses provide a comprehensive range of family planning services. Our doctors have expertise in antenatal care, preconception planning, and STD checks. Contraceptive advice including Mirena and Implanon insertion is available.

  • Early detection of illness;
  • Family planning;
  • Promotion of healthy lifestyle;
  • Skin cancer checks;
  • Sports injuries;
  • Weight reduction;
  • Workers compensation and third party.

  • Children's Health

    Children's HealthBaby Weighing Service. Babies can be booked with our Nurse for weighing, a doctors appointment is not required to use this service. Contact reception for a appointment to have your baby weighed.

    Immunisations. At Tuggeranong Square children's immunisation is regarded an important part of your childs health care. Our doctors take immunising children very seriously. and to ensure all children are immunised Tuggeranong Square Medical Practice doctors BULK BILL for all childhood immunisations. Tuggeranong Square Medical Practice also ensures the Practice Nursing Staff are highly trained in childhood immunisations.


    Women's Health

    Women's HealthOur practice is dedicated to treating a wide spectrum of women’s health concerns. We offer pre-natal, antenatal and postnatal care, contraceptive options, pap screening, and preventative health care advice. We provide assistance, advice and support through all stages of life, recognising the many issues many women may face from adolescence through to the peri and post-menopausal period.

    • Cervical Screening tests;
    • Reproductive health. Including Mirena and Implanon insertion;
    • Shared antenatal care.

    Men's Health

    Men's HealthWe encourage men to present routinely to their GP to discuss all aspects of their health. We provide comprehensive advice and support for men to address the prevention and management of various health conditions. This may include assessments for cardiovascular risk, diabetes, cancer prevention, mental health assessments, STD screening, sports injuries and the importance of sleep as it relates to other areas of health.


    • Preventative Healthcare. Including cardiovascular screening, mental health and cancer checks;
    • Prostate examination.
Alex Koliada, PhD

Alex Koliada, PhD

Alex Koliada, PhD, is a well-known doctor. He is famous for his studies of ageing, genetics and other medical conditions. He works at the Institute of Food Biotechnology and Genomics NAS of Ukraine. His scientific researches are printed by the most reputable international magazines. Some of his works are: Differences in the gut Firmicutes to Bacteroidetes ratio across age groups in healthy Ukrainian population [BiomedCentral.com]; Mating status affects Drosophila lifespan, metabolism and antioxidant system [Science Direct]; Anise Hyssop Agastache foeniculum Increases Lifespan, Stress Resistance, and Metabolism by Affecting Free Radical Processes in Drosophila [Frontiersin].
View All Articles