Why Is My Period Blood Brown?

Brown period blood has various causes but isn’t usually a cause for concern. Period blood that looks brown is typically older, meaning it had more time to oxidize, resulting in a darker hue. However, sometimes, it can indicate a health concern.

In this article, learn more about why your period blood is brown and how to know when it’s normal and when it’s not.

What Causes Brown Period Blood?

You may have noticed brown period blood on your period products during menstruation and wondered if you should be worried. Menstrual blood comes in various colors, and brown period blood is standard. It’s usually a sign of:

• Old blood
• Light flow
• Slow flow

Older blood has more time to oxidize. Exposure to oxygen changes the color of the blood and makes it browner. Consider what it looks like when you get a cut. At first, the blood is bright red, but it turns brown or darker red as it dries. Your menstrual blood has a similar oxidation process, so it may sometimes appear brown.

Possible causes of brown period blood include:

Brown blood during your period is expected. However, sometimes, it can be a side effect or sign of one of the above conditions. Consult a healthcare provider if you are concerned about a change in your menstruation.

How Timing Affects the Color of Period Blood

Having a light or slow flow, in which the blood has more time to oxidize as it leaves the uterus and exits the vagina, is the most common reason for brown period blood. During this time, blood is exposed to oxygen and turns brown.

For most menstruating people, their flow is lightest and slowest at the beginning and end of their period. However, it’s also possible to get brown spotting mid-cycle.

Beginning

You may notice brown period blood at the beginning of menstruation, on the first or second day. In some cases, this is due to a light flow. In other cases, it may be blood left from your previous period.

End

For most people, blood flow gets lighter and slows down at the end of their period. That is why you may also notice brown period blood on the final day or so of menstruation.

Throughout a Period

For people with a very light flow, blood may appear brown throughout their entire period. This is more common if you use a birth control method that can cause lighter periods—such as a hormonal intrauterine device (IUD). Children’s first few periods are often very light and may appear brown.

Mid-Cycle Spotting

It is possible that you could also experience brown vaginal bleeding mid-cycle, particularly when you ovulate. Ovulation is when an egg is released from your ovary. Ovulation bleeding can appear brown.

Is Brown Period Blood Normal? 

In most cases, brown period blood is normal and results from oxidation when your flow is light or slow.

Don’t be concerned if you have brown bleeding at the beginning or end of your period, during ovulation spotting, or with an adolescent’s first few periods.

Below are more situations in which brown period blood is normal:

• Perimenopause: Blood flow slows down significantly during menopause, resulting in brown period blood.
• Early pregnancy: Light brown bleeding during the first 12 weeks of pregnancy is not unexpected. However, you should consult a healthcare provider to report any bleeding during pregnancy.
• Post-sex: You may experience occasional light brown spotting after sex, particularly after vigorous sex or sex with insufficient lubrication. This is due to the dislodging of old blood.
• Postpartum: Bleeding after giving birth (called lochia) is normal. It often has a brown or pinkish tint and lasts around two weeks.
• Side effect from birth control: Some hormonal birth control methods, such as IUDs, implants, and birth control pills, can significantly lighten periods and turn period blood brown.
• Side effect of emergency contraceptive: Plan B, an emergency contraceptive, can cause spotting or light bleeding that may appear brown.

The above situations and their associated brown discharge or bleeding are not generally a cause for concern. However, talk to a trusted healthcare provider if you are worried or have experienced a significant change in your menstrual cycle.

When Is Brown Period Blood Not Normal?

Brown period blood is not always normal. Sometimes, it is a sign of an underlying condition requiring treatment.

Below are situations in which brown period blood is not normal:

• Ectopic pregnancy or miscarriage: Bleeding, accompanied by cramps and pain, is one of the first signs of miscarriage. When this happens, the blood can appear brownish.
• PCOS: PCOS can lead to menstrual changes, and individuals with PCOS may notice light and irregular periods that can appear brown.
• Fibroids and polyps: Uterine fibroids and uterine polyps, which are growths in and on the uterus, can cause irregular menstrual bleeding, including brown blood.
• Infection: An infection in your vagina or cervix, such as an STI, a yeast infection, bacterial vaginosis, or PID, can cause light bleeding that may appear brown.

While brown period blood typically is not something to worry about, consult a healthcare provider if you notice a change in the color of your period blood or vaginal discharge.

Summary

Brown period blood is older blood that has had more time to oxidize. If you have a light or slow flow, which frequently happens at the beginning or end of your period, then noticing brown blood is pretty standard. However, brown period blood can also indicate health conditions like menopause, early pregnancy, infections, PCOS, fibroids, and more.

Talk to a healthcare provider if you notice a change in your menstrual discharge or have accompanying pain or other symptoms.