Menstruation is a natural biological process involving the cyclical shedding of the uterine lining. This monthly discharge has historically been surrounded by misconceptions regarding its cleanliness and safety. This article provides a scientific explanation of what menstrual fluid is composed of and addresses common hygiene concerns.
What Menstrual Fluid Is Made Of
Menstrual fluid is commonly called “period blood,” but it is scientifically distinct from venous blood. The discharge is a complex mixture of several components, only a portion of which is actual blood. On average, blood accounts for approximately 36% to 50% of the total fluid volume released during a period.
The remaining material consists of discarded endometrial tissue, which is the thickened lining of the uterus that built up in preparation for a potential pregnancy. This tissue is mixed with cervical mucus and vaginal secretions. These non-blood components give the fluid a thicker texture and a dark reddish-brown color, differentiating it from the bright red of fresh venous blood.
The fluid also contains biological molecules like sodium, calcium, and iron, along with specific proteins. The lining of the uterus releases an enzyme called plasmin, which acts as an anticoagulant. This enzyme works to prevent the menstrual fluid from clotting inside the uterus. However, heavier flows can sometimes overwhelm the enzyme, resulting in the passage of visible blood clots.
Is Menstrual Fluid Inherently Harmful or Contaminated?
Menstrual fluid is a product of a natural, regenerative process, not a waste product like urine or feces. When within the uterus and upper reproductive tract, the fluid is considered sterile, meaning it does not contain pathogenic bacteria. Shedding the uterine lining is a controlled biological event that prepares the body for the next reproductive cycle.
The perception of the fluid as “dirty” often arises because it interacts with the naturally occurring bacteria of the vaginal canal and the external environment. As the fluid passes through the vagina, it picks up bacteria from the vaginal flora, which includes healthy and normal microbes. Once exposed to air, this combination of fluid and bacteria begins to break down, leading to the metallic or slightly musky odor. This odor is often misinterpreted as a sign of contamination.
The fluid itself is not inherently unhygienic and does not contain high concentrations of harmful pathogens unless a person has an underlying infection. Menstrual fluid is biologically rich, containing viable endometrial stem cells and unique proteins currently being studied for their potential regenerative properties. This composition highlights its function as part of a healing and rebuilding process. The odor and breakdown are external issues related to hygiene management, not internal toxicity.
Maintaining Cleanliness During Menstruation
While menstrual fluid itself is not contaminated, proper external hygiene is necessary to manage the flow and prevent the overgrowth of external bacteria. The most fundamental practice is the regular changing of menstrual products. External products like pads should be changed every four to eight hours, depending on the intensity of the flow.
Internal products like tampons should also be changed every four to eight hours and never worn for longer than eight hours. Leaving a tampon in too long is a primary factor in the development of Toxic Shock Syndrome (TSS), a rare but serious condition. TSS is caused by a toxin released by Staphylococcus aureus bacteria, which can overgrow in the warm, blood-rich environment created by highly absorbent internal products.
To minimize the risk of TSS, use the lowest absorbency tampon that manages the flow and alternate with external products, particularly overnight. Menstrual cups offer a longer wear time, up to twelve hours, but they must be emptied and properly cleaned according to directions. Consistent handwashing before and after changing any product is also essential.
Sexual activity during menstruation requires additional consideration. The presence of menstrual fluid increases the risk of transmitting blood-borne sexually transmitted infections (STIs), such as HIV or Hepatitis C. Furthermore, the vaginal environment becomes less acidic during menstruation, which can increase susceptibility to certain infections. Using barrier protection, such as condoms, remains the most effective method to prevent the exchange of fluids and reduce the risk of STI transmission.