Menstrual pads absorb and contain menstrual fluid. They are a temporary solution requiring consistent upkeep. Wearing a pad introduces a material that holds moisture and heat against sensitive skin. When worn for an extended period, this creates a warm, damp microclimate ideal for bacterial and fungal proliferation. This environment compromises the natural hygiene of the perineal area, leading to discomfort and potential health issues.
Localized Skin Irritation and Odor
Prolonged exposure to moisture and friction from a saturated pad often results in irritant contact dermatitis, commonly called “pad rash.” The damp material constantly rubs the skin, causing chafing and breaking down the skin’s protective barrier. This combination of heat, moisture, and friction mirrors the conditions that cause diaper rash, leading to redness, itching, and inflammation.
Menstrual blood has a slightly alkaline pH, which is higher than the naturally acidic pH (3.8 to 4.2) of the vulvovaginal area. Allowing menstrual fluid to sit on the pad for too long raises the local surface pH. This disrupts the skin’s natural, protective acid mantle, compromising defense mechanisms and making the area susceptible to irritation and microbial overgrowth.
The development of a noticeable odor is a common consequence of infrequent changes. This scent is not caused by the blood itself, which is largely odorless. Instead, it results from the interaction of bacteria with the blood and organic material collected in the pad. As bacteria break down these components, volatile organic compounds are released, creating the unpleasant smell. Regularly changing the pad removes this bacterial reservoir, mitigating odor development.
Elevated Risk of Vaginal and Urinary Tract Infections
The warm, moist environment within a saturated pad encourages the overgrowth of pathogenic organisms. This reservoir of microbes is held against the vaginal and urethral openings, significantly increasing the risk of infection. Two common consequences are bacterial vaginosis (BV) and yeast infections (candidiasis).
Bacterial vaginosis occurs when the vaginal microbiome is disrupted, leading to an overgrowth of anaerobic bacteria. The nutrient-rich menstrual fluid provides a food source, and prolonged dampness facilitates colonization. Similarly, the moisture and heat create an ideal habitat for Candida yeast to multiply, resulting in a yeast infection.
Infrequent pad changes can also elevate the risk of a Urinary Tract Infection (UTI). Bacteria, particularly Escherichia coli (E. coli) from the gastrointestinal tract, can migrate forward from the perineal area. The pad acts as a conduit, keeping these bacteria close to the urethral opening, allowing them to enter the urinary tract.
While Toxic Shock Syndrome (TSS) is often discussed in menstrual hygiene, this condition is overwhelmingly associated with the prolonged use of internal products like high-absorbency tampons. Since menstrual pads are external products, the risk of developing TSS is extremely low when using them exclusively.
Determining the Right Time for Pad Changes
To mitigate the risks of irritation and infection, a consistent schedule for pad replacement is necessary, regardless of saturation level. The general recommendation is to change a pad at least every three to four hours during the day. Even with a light flow, bacteria begin to accumulate and multiply after this time.
This timing requires adjustment based on the heaviness of the flow. On the heaviest days, it may be necessary to change the pad every one to two hours to prevent overflow and reduce microbe concentration. Users should not rely solely on highly absorbent or overnight pads for extended daytime wear.
While these products hold more fluid, their prolonged use creates a false sense of security regarding hygiene. The bacterial load continues to increase even if the pad is not full. The best practice is to change the pad immediately if it feels wet, damp, or uncomfortable, or following physical activity that increases sweat and moisture in the area.