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Cause of Yeast Infection
A fungus called Candida albicans is the primary cause of yeast infections. Factors such as hormonal changes; uncontrolled diabetes; a weakened immune system; or using birth control pills, antibiotics, or steroid medications can lead to changes in the vagina's acidity, which may lead to an overgrowth of yeast. While not a true yeast infection "cause," these factors are associated with an increased risk for the condition.
Nearly 75 percent of all adult women have had at least one genital yeast infection in their lifetime. On rare occasions, men may also experience a genital yeast infection.
A kind of fungus called Candida albicans causes yeast infections. It is normal to have some yeast in the vagina. Usually, yeast is in balance with other organisms. But sometimes the balance is lost, and yeast overgrowth occurs. This imbalance is what causes a yeast infection.
Health experts do not know whether yeast infections can be transmitted sexually. Because almost all women have the fungus in their vaginas, it has been difficult for researchers to study this aspect of the infection.
There are several factors associated with an increased risk of yeast infections in women. While not actual causes, these factors do increase a woman's chances of getting a yeast infection. Yeast infection risk factors include:
- Hormonal changes, such as being pregnant
- Having uncontrolled diabetes mellitus
- Use of oral contraceptives (birth control pills)
- Use of antibiotics
- Use of steroid medications
- Weakened immune systems.
Other factors that may increase the incidence of yeast infection include:
- Douching
- Using perfumed feminine hygiene sprays
- Using topical antibiotics and steroid medicines.
Wearing tight, poorly ventilated clothing and underwear can also contribute to yeast infections.
Written by/reviewed by: Arthur Schoenstadt, MD
Last reviewed by: Arthur Schoenstadt, MD