ladyMenstrual blood is usually bright to dark red and may or may not have some clots. It should not be brown to black and if it is then it needs to be investigated further. The main reason why blood may appear these colors is due to degradation of the blood cells either due to exposure to air (oxidation) over time, the action of bacterial enzymes or exposure of blood to certain chemicals that may cause rapid degradation and discoloration. A brown to black vaginal bleed in a pregnant women particularly if it is accompanied by abdominal pain should be investigated immediately.

Causes of Brown to Black Vaginal Bleeding
It is important to ascertain whether the bleeding is related to a menstrual bleed or not. The presence of other symptoms like pain, discharge preceding or during the bleed, blood clots or pieces of tissue in the blood are all significant in identifying the most likely cause. Remember that a small quantity of brown blood towards the end of a menstrual period is not abnormal and is just degraded blood (“old blood”) being expelled. However, it should not persist for long periods.

The causes include:
1. Retained Periods
2. Miscarriage
3. Pelvic Inflammatory Disease (PID)
4. Uterine Fibroids
5. Cancer

Many of our cycles begin with very dark blood, which often has a brown or almost-black tone. This is older blood. How does your blood get so “old,” exactly, if it’s at the beginning of your flow? Well, there are two ways. To begin with, most of our periods start slowly, with a light flow that becomes heavier as the week goes on. During those light flow days, the blood takes longer to exit your body, and takes on a darker color as it makes its slow exit.

The second way that period blood can become dark has to do with the speeds of our individual periods. Some of us shed uterine lining at a fast, steady rate, and expel every drop of lining each month, finishing with a squeaky-clean uterus (so to speak). But some of us shed our lining more slowly; and when it comes to us slow-bleeders, our uteruses are not always able to completely clean the slate each month.

Thus, we end up with some “leftover” uterine lining that carries over into our next cycle, and is typically the first lining to be sloughed off at the start of your cycle. This lining is darker, which is why you might begin your period with blood that looks more like tar than anything that should come out of a human body. But it’s totally healthy and normal, and nothing to be nervous about.

Warning Signs
A short-lived brown to black vaginal discharge which resolves on its own and does not recur may not necessarily be anything serious. However, it is always advisable to have it checked, preferably by a gynecologist. When profuse and accompanied by pain that is worsening, dizziness and/or weakness then immediate medical attention is necessary. Sometimes the more serious causes of brown to black vaginal bleeding may present with little to no symptoms beyond the discharge.

Foul-smelling discharges should also be taken seriously as this may be a sign of pelvic inflammatory disease (PID). Untreated or delayed treatment of pelvic inflammatory disease remains one of the most common causes of female infertility. A fever, nausea and vomiting along with pelvic pain and discharge (whether it is blood or not) should also be treated as a medical emergency until proven otherwise.