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Why is Your Period Blood Black? Reasons for Black Period Blood

For a majority of women, menses start between the age of 12 and 13. Menses is the regular discharge of mucosal tissue (from the inner uterine lining) and blood through the vagina every month. The American Academy of Obstetricians and Gynecologists states that period may be used as an important health sign for a woman. The various characteristics of the period including its length and color and texture of blood may indicate vital signs regarding your health.

a girl wondering about black period blood

You may notice different colors of menstrual blood that may range from bright red to orange, brown to black. Though most colors may be considered healthy or normal, some may be a reason to visit your doctor. 

Why can your period blood be black? Having unexpectedly black period blood may be really scary. In some cases, it may also be a cause of concern. Learn about the most common reasons for black period blood and find out when you should see a doctor.

Causes of black period blood and discharge

Black period blood and vaginal discharge may look frightening, but it isn’t a cause of concern at all times. You may notice black colored vaginal discharge throughout your menstrual cycle, particularly at the beginning of your periods. 

Black period blood is blood that takes more time to leave your uterus and gets oxidized in the process. This may make this blood darker in color. Hence, it appears as dark brown or black period blood. This blood often has as a resemblance to coffee grounds. 

However, in some cases, you should see your doctor for black colored vaginal discharge. Look out for the following symptoms. 

1. It’s just the start (or the end) of your period

The flow of your menses may be slightly slower at the start and the end of your period. Due to this, the blood in the uterus may take more time to leave the body and get oxidized to appear black or dark brown in color. Hence, you may get black period blood at the beginning (and the end) of the period. 

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woman holding a white sanitary pad without black period blood

2. Something may be stuck inside you

Black period blood may also indicate that a foreign object may be stuck inside your vagina. This may occur if you accidentally placed a second tampon inside your vagina or forgot a tampon after placing it at the end of your menses. 

Other objects that may get stuck in your vagina are condoms, sex toys and contraceptive devices such as sponges, diaphragms, rings, and cervical caps. With time, the object may irritate the vaginal lining and cause a vaginal infection. 

Apart from black blood during period, you may also experience the following symptoms:

  • a foul-smelling vaginal discharge
  • discomfort or itching around and in the vagina
  • rash or swelling around your genital area
  • fever
  • trouble while passing urine

If you notice black period blood or other symptoms as described above and you suspect that something may have stuck in your vagina, then you should visit your doctor. In certain rare cases, women may develop a life-threatening infection known as toxic shock syndrome. 

3. Retained menses — hematocolpos

Retained menses or hematocolpos occurs when menstrual blood can’t leave the vaginal canal and it fills the vagina and uterus. Due to this, the retained blood may turn dark or black with time. The inability of the blood to leave the vaginal canal may occur due to a blockage that is caused by congenital diseases of the vaginal septum or hymen or in certain rare cases an absence of the cervix (known as cervical agenesis). 

In some women, no symptoms may be present. In others, symptoms may be cyclical and manifest in place of an expected period. 

A severe blockage may manifest as a complete absence of menses or amenorrhea. Other complications of hematocolpos are cramping pain in the lower abdomen, endometriosis, and adhesions. 

4. Does it indicate cervical cancer? 

In very rare cases, black blood before period and/or black vaginal discharge may indicate cervical cancer. Although in many women cervical cancer may not produce any symptoms, irregular vaginal bleeding after sex or between periods is among the common signs of cervical cancer. 

In the early stages of cancer, the discharge from the vagina may be clear or white, foul-smelling or watery. It may even contain blood that may turn black or dark brown over time as it leaves your body. 

Apart from the black blood period, you may have the following symptoms during the advanced stages of cervical cancer:

  • fatigue
  • longer or heavier periods
  • pain during sexual intercourse
  • weight loss
  • pelvic pain
  • trouble during urination
  • trouble during defecation
  • swelling in the legs
Doctor and patient discussing black period blood while sitting at the table

5. Lochia

Vaginal bleeding, which occurs 4 to 6 weeks after you deliver a baby is referred to as lochia. This bleeding may begin as a heavy flow that is red in color and contains small blood clots but the flow may get slower after a few days. After four to five days the color of blood may change from red to pink or brown. The color of the blood may even get darker and turn black or dark brown if the flow of blood is particularly slow. 

With time, the color of the discharge may change to yellow or creamy before it stops completely. 

Make sure to visit your doctor if your lochia is bright red in color, you have clots that are larger in size than a plum or you have foul-smelling vaginal discharge during the weeks after delivery. 

6. A missed miscarriage

Black colored bleeding and spotting from the vagina may also indicate a missed miscarriage. It happens when the embryo in your uterus stops developing but doesn’t get expelled by your body. According to estimates, of all pregnancies, about 10 to 20 percent may end in miscarriage. Most of the miscarriages occur before the pregnancy reaches 12th week. 

You may not experience any signs or symptoms of a usual miscarriage such as heavy bleeding or pain. You may still experience signs of pregnancy. When your hormone levels start falling, these symptoms also decrease. In some women, a missed miscarriage is discovered only on a routine ultrasound. 

7. Implantation bleeding

Dark brown or black blood may be an early sign of conception or pregnancy. This is known as implantation bleeding and occurs when the fertilized egg implants into the uterine lining. It may occur 6 to 12  days after the fertilization of the egg. The blood may turn black if it takes more time to leave the vagina. Apart from black blood, other signs and symptoms of early pregnancy may include:

  • frequent urination
  • missed period
  • fatigue
  • swollen and tender breasts
  • vomiting and nausea (morning sickness)

Every woman may not experience the symptom of implantation bleeding. Moreover, it is usually light and lasts for a couple of days. If you are pregnant and experience bleeding then visit your doctor. 

8. Sexually transmitted diseases (STDs)

Black blood before a period may be a sign of a sexually transmitted disease including chlamydia or gonorrhea. Apart from dark brown discharge and black blood before period, other symptoms of STDs may include:

  • foul-smelling discharge
  • burning while urinating
  • pain during sexual intercourse
  • bleeding after or during sexual intercourse
  • pressure or pain in the pelvis
  • itching in the vagina
  • spotting between your periods

Your doctor may treat STDs with antibiotics. Without treatment, they may spread to the reproductive organs and cause pelvic inflammatory disease (PID). 

9. Pelvic inflammatory disease (PID)

Black blood before a period may also indicate pelvic inflammatory disease, which is an infection of your reproductive organs including the cervix and the uterus. Other than black blood, it may cause:

  • pain during sexual intercourse
  • fever without or with chills
  • pain in the lower abdomen and pelvis
  • burning during urination
  • smelly vaginal discharge

Pelvic inflammatory disease may result in complications such as chronic pain in the pelvis and infertility. 

Black period blood treatment

As already stated above, you may get black blood at the beginning of your period, and this needs no special treatment. But when it occurs due to other reasons then it may need treatment. The treatment may depend on the cause of the black blood before period:

  • Your physician may remove the objects stuck in your vagina, particularly, if you are suffering from symptoms such as fever, pain or black blood. 
  • Your doctor may treat infections such as PID and STDs by antibiotics. You should follow all the instructions from your doctor. 
  • Missed miscarriage may resolve on its own.  The alternatives are to have a medication to help the process along. In some cases, the doctor may use the dilation and curettage (D&C) procedure to remove the tissue remaining in the uterus. 
  • In cases of retained menses, the doctor may perform surgery to treat the underlying medical conditions that caused the blockage. 
  • Your doctor may treat cervical cancer with surgery, chemotherapy, radiation therapy or a combination of these therapies. 

When should you see a doctor?

Black blood at the beginning and end of your period is usually normal and isn’t a cause for worry. Bleeding during menses in most women may last between 2 to 7 days and menses may happen every 21-35 days. Having black discharge or bleeding outside this time frame may be considered irregular and you should discuss this with your doctor. 

If you notice black discharge during pregnancy or after delivery of a baby, you should contact your doctor. 

If you are entering menopause and experience black vaginal discharge, then also you should visit your doctor as this may indicate a serious underlying medical condition. 

You should also visit your doctor if black blood:

  • smells bad
  • is accompanied by itching of the vagina
  • is accompanied by cramping or pain

Why is blood black? You may notice black colored blood throughout your menstrual cycle, especially at the start of your menses. There are various reasons why you get black blood. The flow of your period may be slower at the beginning of your period. Hence, you may get black blood at the beginning and the end of the period. Black blood or discharge may also be a sign of a foreign object being stuck in your vagina. It may also indicate cervical cancer in rare cases. Retained menses or hematocolpos may also cause black colored vaginal discharge. You may also get dark colored bleeding four to six weeks after the delivery of your baby, which is known as lochia. A missed miscarriage may also cause black colored bleeding or spotting from the vagina. Black blood may be an early sign of pregnancy due to implantation bleeding. Black blood may also indicate sexually transmitted diseases (STDs) and pelvic inflammatory disease (PID). The treatment of black blood may depend on the cause. Black blood at the beginning and the end of the period is usually normal. You may visit your doctor if black colored bleeding or discharge from the vagina continues for long, is accompanied by pain or cramping and smells bad.


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