Period blood, also known as menstrual fluid, differs from typical human blood found circulating throughout the body because it is a mix of various substances, not just blood.
While normal human blood is primarily composed of red blood cells, white blood cells, platelets, and plasma, period blood is a combination of blood, shedding endometrial tissue (the lining of the uterus), mucus, and vaginal secretions. This unique composition means that period blood has different characteristics than blood drawn from a vein, for example.
One significant difference, highlighted by research, is the hemoglobin level. Hemoglobin, the protein in red blood cells that carries oxygen, is found in much lower concentrations in menstrual blood. According to one study, the typical value of hemoglobin in normal blood samples is considered to be 10-16 gm%, while in menstrual blood, it ranges from 2-5 gm%. This study specifically found that hemoglobin level in menstrual blood is very low as compared to the normal blood samples.
Here's a simplified comparison:
Comparison: Period Blood vs. Normal Human Blood
| Feature | Period Blood (Menstrual Fluid) | Normal Human Blood |
|---|---|---|
| Composition | Blood, endometrial tissue, mucus, vaginal secretions | Red blood cells, white blood cells, platelets, plasma |
| Source | Uterus (shedding lining) and vagina | Circulates throughout the body (veins, arteries, capillaries) |
| Purpose | Shedding of the uterine lining during menstruation | Oxygen transport, nutrient delivery, waste removal, immunity |
| Hemoglobin | Lower concentration (typically 2-5 gm%) | Higher concentration (typically 10-16 gm%) |
| Clotting | Tends to clot less (due to anticoagulants in menstrual fluid) | Clots readily when exposed to air or injury |
Understanding this difference helps clarify why menstrual fluid has a different appearance, consistency, and chemical makeup compared to blood samples taken for medical tests.
