Vaginal pH Explainer: What’s Normal, What Needs Attention
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Sep 2, 2025
Overview
Maintaining an acidic vaginal pH (3.8–4.5) is key for vaginal health, primarily supported by lactobacilli and healthy lifestyle choices. Avoiding practices that disrupt the microbiome and considering targeted interventions can help keep pH in the optimal range. Most symptoms of abnormal vaginal pH are linked to a pH that is too high, leading to dryness, irritation, odor and increased infection risk. If you notice these symptoms, consider consulting a healthcare provider for evaluation and management.
What is pH
The pH level is a measure of how acidic or basic (alkaline) a solution is. It is expressed on a scale from 0 to 14, where 7 is neutral, values below 7 are acidic and values above 7 are basic. The pH scale is based on the concentration of hydrogen ions in a solution: the lower the pH, the higher the acidity; the higher the pH, the more basic the solution.
A pH value of 0–6.9 is acidic. Example: lemon juice, vinegar (Chioson et al., 2018; Nainggolan, 2018)
A pH value of 7 is neutral. Example: pure water (Chioson et al., 2018; Nainggolan, 2018)
A pH value of 7.1–14 is alkaline. Example: soap, baking soda (Chioson et al., 2018; Nainggolan, 2018)
A healthy vaginal pH is typically acidic, ranging from 3.8 to 4.5 in women of reproductive age. This acidity helps maintain a balanced vaginal microbiome and protects against infections.
Several factors including age, sexual activity, hormonal changes, and hygiene practices can influence vaginal pH. In postmenopausal women vaginal pH often rises above 4.5 due to decreased estrogen, which can increase susceptibility to infections and discomfort.
Understanding “Low” and “High” pH: What It Actually Means
It’s critical to interpret pH values correctly. A low pH (e.g., 3.8) means a solution is more acidic, while a high pH (e.g., 8) means a solution is more alkaline. This can be counterintuitive because higher numbers often sound “better,” but in biology, context matters.
A low pH = acidic and in the vaginal environment, that’s usually healthy.
A high pH = alkaline which in the vagina increases the risk of infection and imbalance.
This is because acidic conditions (low pH) suppress the growth of harmful bacteria and support beneficial lactobacilli. In contrast, alkaline conditions (high pH) weaken this defense and make the environment more vulnerable to infections.
That’s why women can’t really have “too low” of a vaginal pH as the healthy range is already low and that’s by design. Most problems stem from pH that is too high, not too low.
Signs of High Vaginal pH
A vaginal pH above 4.5 is considered high and is commonly associated with:
Vaginal dryness (Tucker et al., 2018; Lumbanraja et al., 2021)
Pain during intercourse (dyspareunia) (Tucker et al., 2018; Lumbanraja et al., 2021)
Itching, irritation, and discomfort (Shen et al., 2021; Lin et al., 2021)
Unusual or unpleasant vaginal odor (Shen et al., 2021; Lin et al., 2021)
Abnormal vaginal discharge (often thin, grayish, or yellow-green) (Lin et al., 2021; Shen et al., 2021)
Increased risk of infections such as bacterial vaginosis and trichomoniasis (Lin et al., 2021; Donders et al., 2016; Shen et al., 2021)
High pH is often seen in postmenopausal women, those with bacterial vaginosis, or trichomoniasis. It can also be linked to hormonal changes, frequent sex or certain health conditions (Tucker et al., 2018; Lin et al., 2021; Lumbanraja et al., 2021; Donders et al., 2016).
Practical Tips for Maintaining Optimal Vaginal pH
Avoid unnecessary douching or harsh soaps. These can disrupt the natural acidity (Lin et al., 2021; Ravel et al., 2010). How to wash
Use barrier protection during sex to minimize pH changes from semen (Perelmuter et al., 2025; Da Silva et al., 2011).
Consider lactic acid-based products if recommended by a healthcare provider, as they may help restore acidity (Campaner et al., 2025).
Maintain general health and hygiene; regular physical activity and professional activity are associated with lower (healthier) pH (Da Silva et al., 2011).
