What does it mean if your periods are a blackish colour?

Black or dark brown spotting or menstrual bleeding is usually old blood. If you have black or dark brown spotting or patches on your pad or tampon that happen with your menstrual period, it usually just means that the blood has been in your uterus or vagina for a while — more than a day or so — before coming out. This can happen if your period is heavy, or if you are passing blood clots**.

However, it can also be a sign of an underlying medical condition that needs treatment.

Some possible causes of black or dark brown spotting or menstrual bleeding include:

- Old blood: This is the most common cause of black or dark brown spotting or menstrual bleeding. When blood stays in the uterus or vagina for a while, it can become oxidized and turn a darker color.

- Blood clots: Blood clots are another common cause of black or dark brown spotting or menstrual bleeding. When the lining of the uterus sheds during menstruation, it can sometimes form clots that can look like dark brown or black patches or spots on your pad or tampon.

- Implantation bleeding: Implantation bleeding is the light bleeding that some women experience when the fertilized egg implants in the wall of the uterus. This can happen around the time of your expected period, and it can sometimes look like dark brown spotting or patches.

- Miscarriage: Miscarriage is the loss of a pregnancy before the 20th week of gestation. Black or dark brown spotting or bleeding can be a sign of miscarriage, especially if it is accompanied by other symptoms such as abdominal pain or cramping.

- Ectopic pregnancy: An ectopic pregnancy is a pregnancy that occurs outside of the uterus, usually in the fallopian tube. Black or dark brown spotting or bleeding can be a sign of an ectopic pregnancy, especially if it is accompanied by other symptoms such as abdominal pain, nausea, or vomiting.

- Sexually transmitted infection: Some sexually transmitted infections (STIs) can cause black or dark brown spotting or bleeding, such as chlamydia and gonorrhea.

- Uterine fibroids: Uterine fibroids are noncancerous growths that can form on the inside or outside of the uterus. Fibroids can cause heavy or irregular menstrual bleeding, including black or dark brown spotting or patches.

- Endometriosis: Endometriosis is a condition in which the tissue that lines the uterus (the endometrium) grows outside of the uterus. Endometriosis can cause heavy or irregular menstrual bleeding, including black or dark brown spotting or patches.

- Adenomyosis: Adenomyosis is a condition in which the endometrium grows into the muscle of the uterus. Adenomyosis can cause heavy or irregular menstrual bleeding, including black or dark brown spotting or patches.

- Cancer: In rare cases, black or dark brown spotting or menstrual bleeding can be a sign of cancer, such as endometrial cancer or cervical cancer.

Black or dark brown spotting or menstrual bleeding can have many possible causes, some of which are more serious than others. It is important to see a doctor if you are concerned about your discharge, especially if you have other symptoms such as abdominal pain, cramping, nausea, or vomiting.