Yeast Infection Causes and Risk Factors Everyday Health MenuNewslettersSearch Yeast Infection What Causes Yeast Infections Medication health conditions and lifestyle factors can all cause a yeast infection By Joseph Bennington-CastroMedically Reviewed by Sanjai Sinha, MDReviewed: May 29, 2018Medically Reviewed Medication health conditions and lifestyle factors can all cause a yeast infection An overgrowth of C. albicans (or other Candida species) in the vagina causes a yeast infection.Cavallini James/AlamyThree out of every four women will have at least one vaginal yeast infection at some point, and up to half of all women will have more than one. (1) In other words, this type of vaginal infection is extremely common. Yeast infections can occur in several places on the body. The most common areas are:The mouth, where the infection is called thrush (2)On the feet, as athlete's footOn the genitals When a yeast infection develops in a woman's vagina, it causes a type of vulvovaginitis, or inflammation of the vulva and vagina. Vaginal yeast infections are also known as vaginal candidiasis, vulvovaginal candidiasis, and candidal vaginitis. (3) Yeast — a single-celled fungus — can also cause infection in overweight people who have folds of skin that rub against each other, creating a dark and moist environment in those folds. These infections are called candidal intertrigo. (4) We normally have yeast all over our bodies and in our guts, and it plays an important role as it lives side by side with bacteria. "When there is an imbalance in the normal flora [environment] of the vagina, the yeast can grow heavier and cause what we know of as a symptomatic yeast infection," says Rosanna Gray-Swain, MD, an obstetrician-gynecologist in St. Louis. "In the vagina, these symptoms usually include itching, discharge, redness, and burning," she says. (3) What Causes Vaginal Yeast Infections Candida albicans is a species of yeast that's a normal part of the microbes that live in your gastrointestinal tract. Small amounts of the yeast also live in various warm, moist areas throughout the body, including the mouth, rectum, vagina, and parts of your skin. C. albicans is not the only species from the Candida genus that lives in the body. Other common species include C. glabrata, C. parapsilosis, C. tropicalis, and C. krusei. These five species of yeast cause more than 90 percent of vaginal yeast infections, but most of these infections are due to C. albicans. (5) Some studies estimate that about 20 percent of asymptomatic, healthy women have Candida living in their vaginas, according to a report published in the journal The Lancet. (1) But C. albicans comprises 85 to 95 percent of the Candida yeast strains isolated from the vagina, the report notes. An overgrowth of C. albicans (or other Candida species) in the vagina causes a yeast infection. Candida species also cause thrush and candidal intertrigo (Candida is commonly found in the mouth but not on the skin, except in warm, moist areas). But athlete's foot is caused by different fungal species, in particular Trichophyton rubrum, T. interdigitale, and Epidermophyton floccosum. (6) How Yeast Infections Develop Your body is normally very good at regulating itself, maintaining all the right chemical levels for good functioning. Additionally, the population of C. albicans is naturally kept in check by the bacteria and other microorganisms that make up your microbiome, the community of microorganisms that inhabit your body. Sometimes, though, problems will occur that alter that chemistry, throwing certain bodily functions off-balance, as well as disturbing the microbial balance. When this happens, the scales may tip in favor of C. albicans, allowing the fungus to grow out of control and cause a yeast infection. (1) Common symptoms of vaginal yeast infections include:Vaginal itching and a burning sensation in the vaginal region, including the labia and vulvaWhite vaginal discharge that's sometimes described as being similar in consistency to cottage cheese (but does not smell)Pain during urination or sexRedness and swelling of the vulva (7) What Lifestyle Factors Contribute to Yeast Infections A variety of lifestyle factors may contribute to the development of a vaginal yeast infection. For example, wearing tight underwear or underwear made from a synthetic fabric that doesn't let the area "breathe" encourages yeast overgrowth. Absorbent cotton or silk underwear is best. Additionally, failing to promptly change out of wet swimsuits or exercise clothing fosters an environment perfect for yeast growth. Using certain over-the-counter feminine hygiene products, such as douches, scented sprays, and even bubble bath, may disrupt the natural microbial balance in the vagina, resulting in a yeast infection. (8) Being overweight can also contribute to yeast infections, both in the vagina and in the folds of the genital area, as can eating a diet high in sugar (a food source for yeast). What Medical Conditions Can Increase Infection Risk Many women get their first yeast infection when they are pregnant or are on birth control pills. Some women get vaginal infections from yeast overgrowth when they have their periods, due to hormonal changes (yeast infections are less common in postmenopausal women and girls who have yet to menstruate). If you have diabetes, you may also find that you experience frequent or chronic yeast infections if your blood sugar is not well controlled. Illnesses that lower your immunity, like HIV or AIDS, can also lead to frequent yeast infections. (9) How Antibiotics and Yeast Infections Are Connected Some antibiotics are known to encourage yeast overgrowth by killing off normal genital bacteria, which throws off the balance of the vaginal microbial community and makes it easier for yeast to thrive. Still, most women who take antibiotics do not develop symptomatic yeast infections. This risk is typically only associated with the 20 percent of women who are already colonized with Candida. (1) Using probiotics while on antibiotics may help by restoring good bacteria. The best sources of probiotics are organic yogurt with live bacterial cultures and supplements that contain "good" bacteria — look for the words "lactobacillus" or "acidophilus" on the label. Note that solid evidence showing probiotics help prevent yeast infections is lacking. But there's little harm in trying probiotics. (10) How Steroids and Yeast Infections Are Connected Steroids are another type of medication that can cause people to develop an infection from yeast. The higher the dose and the longer you use them, the greater the risk, but even low-strength topical steroid creams may make yeast infections more likely by damping the body's natural immune defenses. (11) The good news is that most yeast infections are easily treated with antifungal creams or suppositories purchased over the counter or through prescription. If you think you have a vaginal yeast infection, speak with your doctor to discuss your treatment options. It's not recommended for women to use OTC creams before getting diagnosed by their doctors, because the symptoms of yeast infections are similar to those of other vaginal infections, such as bacterial vaginosis. Most yeast infections subside within a few days after treatment starts. (3) Resources We LoveNEWSLETTERS Sign up for our Women' s Health Newsletter SubscribeBy subscribing you agree to the Terms of Use and Privacy Policy. Editorial Sources and Fact-Checking ReferencesSobel JD. Vulvovaginal Candidosis. The Lancet. July 2007.Candida infections of the mouth, throat, and esophagus. Centers for Disease Control and Prevention. August 4, 2017.Vaginal Candidiasis. Centers for Disease Control and Prevention. August 4, 2017.Parker ER, Candidal Intertrigo. UpToDate. July 14, 2017.Sardi JCO, Scorzoni L, Bernardi T, et al. Candida Species: Current Epidemiology, Pathogenicity, Biofilm Formation, Natural Antifungal Products and New Therapeutic Options. Journal of Medical Microbiology. January 2013.Havlickova B, Czaika VA, Friedrich M. Epidemiological Trends in Skin Mycoses Worldwide. Mycoses. August 2008.Yeast Infection (Vaginal). Mayo Clinic. September 18, 2015.Vaginal Yeast Infections. KidsHealth. April 2015.Sobel JD. Patient Education: Vaginal Yeast Infection (Beyond the Basics). UpToDate. October 3, 2017.Xie HY, Feng D, Wei DM, et al. Probiotics for Vulvovaginal Candidiasis in Non-Pregnant Women. Cochrane Database of Systematic Reviews. November 2017.Medications That Weaken Your Immune System and Fungal Infections. Centers for Disease Control and Prevention. January 25, 2017. SourcesUniversity of Rochester Medical CenterThe Center for Young Women’s HealthShow Less The Latest in Yeast Infection Home Remedies for Vaginal Yeast InfectionsMedications can be very effective, but some people still prefer natural options. 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