Period blood colors:
Bright red period blood: Bright red period blood is blood that was produced by the body recently. During a period, this just means what’s being shed was recently released in to the uterus. You may see more bright red blood if you have a lighter flow or frequent periods. Bright red period blood is also common in the beginning your cycle.
Dark period blood: Dark blood is essentially older blood. This means it’s been stored in the uterus longer and had more time to break down, may have begun to coagulate in the vaginal canal, or may have been exposed to air. Many women notice darker red blood when they first wake in the morning.
Brown or Black period blood: Black or brown period blood colors are the oldest blood; most women notice these colors at the tail end of their period or during light spotting at the beginning. It usually isn’t that heavy. This may have been blood that was stuck in folds of the uterine wall or if you have infrequent periods, was just the first to enter so long ago. Brown blood is also sometimes seen when bleeding is very light and takes some time to make it’s way out so to speak. Period blood clots also frequently appear darker, but we’ll get to that in a moment. You can read more about brown discharge, rather than actual bleeding, here.
Period Blood Textures:
Heavy period clots: Heavy clotting is usually prescribed to heavy periods. As blood is expelled, the body releases anticoagulants to keep it from clotting, but if your period is heavy, sometimes the blood flow and speed doesn’t give those anticoagulants time to work, and clots are the result. Clots can occur in any color of blood, though they are more commonly dark in color. This makes sense, because when you’re expelling older blood it has had time to build up a lining in the uterus as it should, and naturally a buildup of blood would create a heavier flow than fresh blood, which would be bright red in color. Frequent heavy clotting or clots larger than the size of a quarter can be a sign of a more serious problem and should be evaluated by your doctor.
Slippery and jelly-like period blood: Menstrual blood that seems almost slippery with a jelly-like texture is mixed with high levels of cervical mucus. Cervical mucus is always present in the vagina, even during menstruation, if your flow is light, it may be sufficient to alter the appearance of blood texture. You may also notice this after a bowel movement when more mucus is pushed from the cervix or if you’ve recently been pregnant. Period blood after a pregnancy is generally quite unique giving off a distinct smell of, well, decay.
Thin period blood: Thin blood is being properly prevented from clotting. It is often bright red in color and accompanies a light to moderate flow. Fresh blood will appear thinner as will blood that is light enough that it’s mixing with cervical fluid.
Tissue in period blood: If there is what appears to be actual tissue within your period blood it is possible you suffered an early miscarriage. Miscarriage tissue typically is described as being grey to white in color. It does not look like a common blood clot. Another type of tissue, called a decidual cast may also be shed in cases. Decidua is part of the mucus membrane of the uterus and is often described as looking like “chicken skin.” Decidual cast passage can be a sign of ectopic pregnancy or hormonal imbalance, but in other cases it just happens once and never happens again. If you have continued pain after passing a decidual cast, you should seek medical attention. (You can do an online image search for both types of tissue to get an idea of the difference, but due to the graphic nature of those images I will not share them here.)
Keep in mind, that in most cases, changes in period blood colors or texture are entirely irrelevant and don’t suggest any health problem. However, prolonged changes such as frequent heavy periods, odors, irregular periods, short periods, and/or severe pain during menstruation should be evaluated.
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