The color of a person's period blood can relay vital health information. For example, orange or grey blood can sometimes indicate a vaginal infection.

During menstruation, the body sheds tissue and blood from the uterus through the vagina. This bloody discharge can vary from bright red to dark brown or black depending on how old it is.

Blood that stays in the uterus long enough will react with oxygen (oxidize). Blood that has had time to oxidize appears darker.

Hormonal changes and health conditions can also affect the color and texture of period blood.

In this article, we present a period blood chart and discuss what the different colors of period blood can mean. We also cover color changes during a period, what clots mean, and when to see a doctor.

Colors of period blood infographic <br>Stephen Kelly, 2019</br>
Image credit: Stephen Kelly, 2019

Bright red blood indicates fresh blood and a steady flow. A period may start with bright red bleeding and darken towards the end of the period. Some people may find that their blood stays bright red throughout their period.

Unusual spotting or bleeding between menstrual cycles may be a sign of a sexually transmitted infection, such as chlamydia or gonorrhea. Growths in the uterine lining, called polyps or fibroids, can also cause unusually heavy bleeding.

Rarely, bright red bleeding may be a sign of cervical cancer. Other symptoms of cervical cancer include:

  • heavier periods
  • periods that last longer than normal
  • bleeding after sexual intercourse
  • foul-smelling vaginal discharge
  • pain in the lower back, pelvis, or legs
  • loss of appetite
  • unexplained weight loss

Pink blood or spotting can occur when period blood mixes with cervical fluid.

Using hormonal birth control can lower estrogen levels in the body, which can lead to a lighter flow with a pinkish hue during periods.

Sexual intercourse can create small tears in the vagina or the cervix. Blood from these tears can mix with vaginal fluids and exit a person's body as pink discharge.

Other causes of pink period blood can include:

  • significant weight loss
  • unhealthful diet
  • anemia

Pregnancy

During pregnancy, pink discharge that contains tissue and occurs alongside cramps may indicate a miscarriage. It is important for women who experience vaginal bleeding while pregnant to see their doctor or obstetrician.

Blood that mixes with cervical fluid can also appear orange.

Orange blood or discharge often indicates an infection, such as bacterial vaginosis or trichomoniasis. People with orange blood should check for other telltale symptoms, such as vaginal itching, discomfort, and foul-smelling discharge.

Although orange period blood or discharge does not always indicate an infection, it is a good idea for a person to see a doctor or gynecologist for an evaluation.

It is advisable for people to consult a doctor or gynecologist for any of the following symptoms:

Anyone who is pregnant and notices any bleeding or unusual vaginal discharge should speak with their doctor or obstetrician.