Risk Factors for Vaginal Infections

Why infections happen

Vaginal infections are not about being “unclean.” They happen when the natural balance of bacteria and yeast in the vagina is disrupted. Normally, protective Lactobacillus bacteria produce lactic acid that keeps the pH slightly acidic (3.8–4.5), making it hard for harmful microbes to thrive.

When this balance shifts, bacterial vaginosis (BV), yeast infections, or other conditions can develop. Some factors increase the chances of this happening — understanding them helps you reduce risk and respond early.

The main risk factors

1. Antibiotics

• Why: Antibiotics don’t discriminate — they kill harmful bacteria but also reduce the protective Lactobacillus in your vaginal microbiome.

• Impact: This can trigger yeast overgrowth (candida infections) or make you more vulnerable to BV.

• Evidence: Studies show that women who take broad-spectrum antibiotics are up to 2–3 times more likely to develop a yeast infection in the following weeks.

• Tip: If you need antibiotics, consider taking a vaginal probiotic afterwards to help restore balance (but ask your doctor before starting).

  
  

2. Hormonal changes

• Menstrual cycle: Around and after menstruation, pH temporarily rises (less acidic), which favors BV-causing bacteria.

• Pregnancy: Higher estrogen levels increase glycogen in the vagina, feeding yeast growth and raising risk of candidiasis.

• Menopause: Lower estrogen leads to dryness, thinning of tissues, and fewer protective Lactobacillus, making infections more common.

• Tip: Track your cycle to understand when you’re more vulnerable. Gentle moisturizers or pH-balancing gels can support vaginal health during low-estrogen phases.

  
  

3. Sexual activity

• BV: Not an STI, but sex can change the bacterial mix in the vagina, especially with new or multiple partners.

• Trichomoniasis: This is a sexually transmitted infection caused by Trichomonas vaginalis — around 156 million new cases occur worldwide each year (WHO). It requires prescription treatment.

• Condom use: Can lower risk of trichomoniasis and reduce pH disruption.

• Tip: If you notice symptoms after sex (odor, irritation), it may be a sign your microbiome was disturbed — keep track of patterns.

   

4. Hygiene products

• Douches: Strongly discouraged — WHO and CDC warn they increase risk of BV and pelvic inflammatory disease.

• Perfumed wipes/sprays: These remove protective bacteria and irritate the lining.

• Reality check: Vaginas are self-cleaning. Normal discharge is healthy, not something to be washed away.

• Tip: Stick to warm water or mild, fragrance-free cleansers externally only. Never douche.

  
  

5. Clothing choices

• Tight or synthetic underwear: Traps heat and moisture, creating conditions yeast thrives in.

• Safer choice: Cotton underwear allows airflow and reduces infection risk.

• Extra tip: Change out of sweaty gym clothes quickly to avoid prolonged dampness.

  
  

6. Stress and lifestyle

• Stress: Raises cortisol, which weakens the immune system and reduces your body’s ability to keep microbes balanced.

• Sleep & diet: Poor sleep and high sugar intake are linked to higher rates of yeast overgrowth.

• Tip: Support your microbiome with enough sleep, balanced diet, and stress management — they matter as much as external factors.

Factors you can’t fully control

• Natural hormonal changes (periods, pregnancy, menopause)

• Genetic predisposition (some women are more prone to BV or yeast)

• Age (younger women are more likely to experience recurrent yeast, while BV is most common in reproductive age)

These aren’t your fault — they’re part of how bodies work. The key is to know when you’re more vulnerable, so you can take supportive steps.

Factors you can control

• Avoid douches, perfumed wipes, or deodorant sprays

• Choose cotton underwear and change out of damp clothes

• Use antibiotics only when prescribed

• Support your microbiome with probiotics or pH-balancing products if needed

• Track changes in your discharge to spot patterns early

Clarity, not blame

Vaginal infections are common, and having one doesn’t mean you did something “wrong.” Knowing the risk factors is about awareness, not guilt. It helps you understand your body’s rhythms and protect your balance.

Santelle makes this easier: discreet monthly check-ins that give you reassurance when things look normal, and guidance when it’s time to act.