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Why is my period blood black?

It’s common for period blood to vary in color from bright red to dark brown or even black. The color of menstrual blood can be influenced by a number of factors, so black period blood does not necessarily indicate a serious health problem.

What causes black period blood?

Here are some potential causes of black menstrual blood:

  • Old blood: Blood ages in the uterus before being shed during your period. Older blood tends to be darker.
  • Clotted blood: Blood clots in the uterus or vagina may appear black or dark brown.
  • Endometriosis: This condition causes bleeding from endometrial tissue outside the uterus, which can result in darker old blood.
  • Adenomyosis: This condition causes the uterine lining to grow into the muscular wall, leading to clotted, dark old blood.
  • Fibroids: These noncancerous growths in the uterus can cause heavy, dark periods.
  • Medications: Some birth control pills or intrauterine devices (IUDs) can cause spotting, which may appear dark or brown.
  • Pregnancy complications: Retained products of conception after miscarriage or ectopic pregnancy may cause dark discharge.
  • Cervical or endometrial polyps: These growths on the cervix or uterine lining can cause abnormal bleeding.
  • Cervical cancer: In rare cases, dark period blood may be a sign of cervical cancer.

Is black period blood normal?

While bright red blood is most common during menstruation, dark or black blood is generally nothing to worry about. Here are some pointers on when black period blood is normal:

  • On the first day: seeing dark blood at the start of your period is very common.
  • Mixed with bright red blood: dark blood often mixes with fresh red blood.
  • At the end of your period: old blood left in your uterus often appears dark brown or black.
  • With blood clots: clotted blood often looks dark or black.
  • With a consistently light flow: slow light periods often produce darker blood.

So in most cases, black or dark menstrual blood is a normal variation. However, if your period flow is unusually heavy or lasts longer than normal, mention the black blood to your doctor.

When should black period blood be evaluated?

See your gynecologist or healthcare provider if you notice these concerning changes along with black period blood:

  • Unusually heavy flow
  • Periods lasting more than 7 days
  • Severe menstrual cramps
  • Foul odor coming from vaginal discharge or blood
  • Dizziness, weakness, or shortness of breath during your period
  • Bleeding between periods or after sex

While black blood alone may not indicate a problem, paired with these symptoms it could signal an underlying health issue needing medical attention. Make an appointment with your doctor right away if you have black period blood along with:

  • Prolonged or sudden heavy bleeding
  • Severe abdominal or pelvic pain
  • Fever or chills
  • Bad-smelling vaginal discharge

When to see a doctor

You should make an appointment with your doctor if you notice any of the following:

  • Your period lasts longer than 7 days
  • You are soaking through more than one pad or tampon every hour for multiple hours
  • You pass blood clots larger than the size of a quarter
  • You experience severe pain during your period
  • You have symptoms like fever, chills, dizziness, or fainting during your period

Seeking prompt medical care is recommended if you experience black period blood along with any of the above symptoms.

What causes heavy or abnormal uterine bleeding?

Some potential medical causes of heavy or abnormal bleeding that may result in black period blood include:

  • Uterine fibroids: Noncancerous tumors in the uterus that can cause heavy and prolonged periods.
  • Adenomyosis: A condition where the uterine lining grows into the muscular uterine wall, leading to painful, heavy periods.
  • Endometriosis: Tissue similar to the uterine lining implants outside the uterus, and can cause heavy bleeding.
  • Cervical polyps: Small, benign growths on the cervix that can cause abnormal bleeding between periods.
  • Endometrial polyps: Overgrowths of the uterine lining that often cause irregular spotting.
  • Hormonal imbalances: Issues with hormones like estrogen can cause heavy bleeding, especially approaching menopause.
  • Pregnancy complications: Ectopic pregnancy, miscarriage, or retained products of conception may have dark, abnormal bleeding.
  • Medications: Blood thinners, antidepressants, birth control pills, and IUDs can sometimes increase menstrual flow.
  • Pelvic inflammatory disease: This infection of the reproductive organs can cause bleeding between periods.
  • Cervical cancer: In rare cases, cervical cancer may present with dark, heavy periods.

There are also other medical conditions that can contribute to heavy periods and dark menstrual blood flow. Proper diagnosis from a doctor is important to determine the exact cause.

Diagnosing the cause of black period blood

To get to the root of abnormal uterine bleeding and black period blood, your doctor may recommend:

  • Physical exam to check for signs of bleeding, pain, or pelvic masses.
  • Pregnancy test to rule out complications like miscarriage or ectopic pregnancy.
  • Blood tests to check for anemia, hormone levels, and other markers.
  • Pap smear to detect any cervical cell abnormalities.
  • Transvaginal ultrasound to get images of the reproductive organs.
  • Biopsy of the uterine lining to test for cell changes, cancer, or infection.
  • Hysteroscopy to insert a camera into the uterus to see inside it.
  • Laparoscopy for a camera-assisted look at the pelvic region if needed.

Based on your test results, your doctor will determine if you have any underlying conditions contributing to dark menstrual blood flow.

Medical treatments for black period blood

Treatment will depend on the cause, but may involve:

  • Hormonal birth control like the pill, patch, ring, or hormonal IUD to regulate menstrual cycles.
  • NSAID pain relievers like ibuprofen to reduce heavy bleeding and cramping.
  • Antibiotics if pelvic inflammatory disease or infection is the cause.
  • Medications to shrink uterine fibroids or treat other conditions.
  • Endometrial ablation to destroy the uterine lining and control heavy bleeding.
  • Polyp removal or hysteroscopic resection to eliminate uterine polyps or tissues.
  • Uterine artery embolization to block blood flow to fibroids.
  • Myomectomy to surgically remove uterine fibroids.
  • Hysterectomy to remove part or all of the uterus if other treatments fail.

Your doctor will discuss options for stopping abnormal bleeding and regulating your cycles. With treatment, black menstrual blood should resolve.

When to seek emergency care

You should go to the emergency room or call 911 if you experience:

  • Bleeding heavier than your typical heaviest period day
  • Soaking more than 2-3 pads or tampons per hour for 2 hours straight
  • Passing blood clots bigger than a lemon
  • Severe abdominal or pelvic pain
  • Lightheadedness or dizziness with bleeding
  • Chest pain or trouble breathing

Extreme heavy bleeding or suspected internal bleeding warrants emergency care to stabilize you, stop bleeding, and prevent shock.

Can I have sex during black period blood?

It is generally safe to have sex during your period, even when passing dark or black menstrual blood. However, you may opt to avoid sex during your heaviest flow days or when passing large clots, which can be messy.

Use a condom or menstrual cup to minimize the mess. Avoid chemical irritants in douches, oils, and lubricants which may sting exposed vaginal tissue. Drink plenty of water and urinate after sex to lower infection risk.

Avoid sex if you have a fever, foul odor, burning with urination, or other symptoms indicating vaginal infection. See your doctor to treat any infections before resuming sexual activity.

Tips for managing black period blood

To handle dark menstrual flow:

  • Use overnight pads or period underwear to absorb heavy flow.
  • Take ibuprofen to reduce heavy bleeding and cramping.
  • Apply a heating pad to ease menstrual cramps.
  • Drink plenty of fluids to replace lost blood and prevent dehydration.
  • Get enough iron if you have low ferritin levels or anemia.
  • See your gynecologist for an evaluation if you have concerns.

While passing dark clots or black blood can seem alarming, it usually is not cause for concern. But do make an appointment with your doctor if heavy bleeding persists or you develop other symptoms.

When to worry about black period blood

Black discharge alone is rarely an emergency. But seek prompt medical care if you have black blood along with:

  • Bleeding longer than 7 days
  • Changing more than 1 pad per hour for multiple hours
  • Severe abdominal or pelvic pain
  • Weakness, dizziness, or confusion
  • Fever or chills
  • Foul vaginal odor

Sudden heavy bleeding warrants an immediate trip to urgent care or the ER to prevent complications like anemia and shock. Call 911 if bleeding is severe.

Precautions with black period blood

Take these precautions if you have dark menstrual flow:

  • Avoid using tampons, which can absorb and retain blood clots.
  • Change pads, period underwear, or menstrual cups frequently.
  • Don’t use douches, which can irritate vaginal tissue.
  • Refrain from vaginal sex during heavy flow days.
  • Check for symptoms like fever that could indicate infection.
  • Watch for dizziness, weakness, or shortness of breath.

Be attentive to your symptoms and see a doctor promptly if you have concerns about prolonged heavy bleeding or other changes along with black discharge.

Frequently asked questions

Why is my period blood suddenly black?

Sudden black blood may be due to retained old blood mixing with fresh blood during your period. Clotting can also cause blood to appear black. Sudden heavy or prolonged bleeding warrants medical attention to determine the cause.

What does it mean when your menstrual blood is black?

Black menstrual blood typically indicates older blood or clotted blood being shed from your uterus. This darker blood is a common, natural variation during your period. But see your doctor if you have other symptoms like heavy bleeding.

Is old period blood black?

Yes, menstrual blood that remains in the uterus for an extended time before being shed will usually appear dark brown or black when it exits the body during your period. This older blood has had time to oxidize and take on a darker color.

Can you get blood clots during your period?

Passing blood clots during menstruation is common. Small clots usually are not a concern. Large clots over 1 inch may warrant medical attention if you are also bleeding heavily. Clots often appear black or dark red.

Is black discharge always a sign of something serious?

No, having black vaginal discharge or menstrual blood does not always indicate something serious. Dark brown or black discharge is common at the beginning or end of your period as older blood exits. But do see a doctor for evaluation of abnormal bleeding.

Summary

In summary, black menstrual blood is generally nothing to be alarmed about. Blood can appear dark brown, purple, or black due to:

  • Older blood aging in the body
  • Clotting of menstrual blood
  • Slow, light periods producing darker flow

However, if heavy, prolonged bleeding accompanies black discharge, or you have other symptoms like pain or fever, see your gynecologist promptly. Sudden severe bleeding may require emergency care.

With evaluation and treatment, abnormal uterine bleeding and dark period blood can be managed. Monitor your symptoms and discuss concerns with your healthcare provider.