Why Is My Period Blood Black? Should I Be Worried?

Here's a fun fact:  it's perfectly normal for the color of your menstrual blood to change while you're having your period. You might see pink, brown, or different shades of red from light to dark. Yes, it's all perfectly normal and not a cause of concern. Black-period blood, on the other hand, is also possible, and while it might make you worry about the worst (sexually transmitted infections or a warning sign of cervical cancer), it's also normal and does not require medical attention.

Although black-colored period blood is usually nothing to worry about, it can occasionally be a sign of a more serious health condition. So, if you're unsure what's normal and what's not, don't panic. We spoke with Dr. Kimberly Fallon, MD, FACOG, PAG Certified, an OB/GYN with Holy Name Medical Center in New Jersey, about what to expect with black period blood and when it's a good time to go to a doctor.

Why is my period blood black?

While the amount of vaginal bleeding differs from woman to woman, according to Dr. Fallon, it's common for all women's period blood to change color over the course of their cycle. "During menstruation, it is common to see bright red and dark red-colored menstrual blood, but it is also normal to see brown or black blood at the beginning and end of your period," she tells Today's Parent.

"Blood that remains in the uterine lining or vagina for a longer time can oxidize, causing it to turn darker red, brownish red, dark brown, or even blackish in color and resembling coffee grounds."

Is black period blood bad?

Considering that menstrual blood changes color over the course of your cycle, a 2020 article from The Cleveland Clinic states that black period blood is typically nothing to worry about. However, if you are experiencing black period blood during an irregular period, it may be a good idea to see your gynecologist for further evaluation, especially if this is not your typical cycle experience.

Black period blood may be cause for concern if you have a strong blood flow, according to Dr. Fallon, as it could result in anemia."If you soak more than a full heavy flow pad or tampon every hour, and/or pass very large blood clots with menses, this could be a cause of concern," she tells Today's Parent.

"Bleeding longer than seven days with each menstrual cycle is also a sign to call your OB/GYN." Additional anemia symptoms include pale skin, exhaustion, and lightheadedness, according to the Centers for Disease Control and Prevention.

Does black period blood mean I'm pregnant?

Black period blood isn't typically related to early pregnancy, but according to Dr. Fallon, it can occasionally signal a more serious issue, like a miscarriage. "Passing darker blood or dark tissue can also be a sign of an early miscarriage," Dr. Fallon says. "Therefore, a pregnancy test should always be performed to confirm this."

Darker-period blood has also been associated with ectopic pregnancy, which, according to the National Health Service (NHS), happens when a fertilized egg implants itself outside of the womb in the fallopian tubes. According to the NHS, symptoms of an ectopic pregnancy include missed periods, abdominal and pelvic pain, and vaginal bleeding. However, it usually has a watery consistency and a brown color.

Is black period discharge normal?

Due to hormonal changes in the body, your period blood color can vary from the beginning to the end of your cycle. With this in mind, brown or black period blood accompanied by some vaginal discharge is typically normal, according to the Cleveland Clinic.

Consider visiting a gynecologist for additional testing if you have any underlying concerns or are experiencing brown period blood with irregular periods, have a foul-smelling discharge or weight loss .

FAQs

How long can black period blood last?

According to Dr.  Fallon, brown period blood and black period blood shouldn't persist for more than a few days at the start and end of your cycle. But if bleeding continues for a few weeks, it's best to get in touch with a doctor for a more thorough assessment. This could be indicative of anemia, and pale skin, exhaustion, and lightheadedness are signs to watch out for.

When should I see a doctor if I have black period blood?

Period blood can turn black once it oxidizes because it sits in the uterus or vagina for the longest time, Dr. Fallon explains. Although this is considered normal, you should seek medical attention if you experience black-colored period blood in cycles lasting more than seven days or in between irregular periods.

Is black period blood normal? 

The flow and duration of the blood's stay in the uterus can cause menstrual blood to change color during your cycle, from bright red to pink, brown, or black, according to an article published by New York University.

However, if dark brown or black period blood lasts longer than a week or is accompanied by a heavy flow (or an unusually light flow), you should consult a doctor or gynecologist for further evaluation.

What can I do to stop black period blood from staining my underwear?

Consider wearing absorbent black period underwear layered with the sustainable period products of your choice. Tampons, cups or pads are all worthwhile choices.

Period underwear is designed to trap blood of all colors and release stains in the laundry.

Experts:

• Dr. Kimberly Fallon, MD, FACOG, PAG Certified, an OB/GYN with Holy Name Medical Center in Teaneck, NJ