Yeast infections are caused by the Candida genus of yeasts (a single cell fungus), most often Candida albicans.
Research shows that C. albicans colonizes the vaginas of about 20 percent of women and 30 percent of pregnant women. (1)
Though this colonization doesn't cause symptoms, symptomatic yeast infections can develop when the balance of microbial communities within the body gets thrown off by things like medication (antibiotics, in particular), hormonal changes, and the overuse of feminine hygiene products.
There are numerous drugs that can be used to treat vaginal yeast infections.
They can be purchased over-the-counter (OTC) or with a prescription, and take the form of an antifungal cream, ointment, suppository, or medicated tampon. An oral tablet is also available.
It's important to get diagnosed by your doctor before trying OTC drugs — especially if you've never had a yeast infection before — because the symptoms of yeast infections are similar to other types of vaginal infections, including bacterial vaginosis (a bacterial infection of the vagina) and trichomoniasis (a sexually transmitted infection). (2)
Standard medicines for yeast infections are all a part of the class of antifungal drugs called azoles. They include:
Prescribed medication may also come with additional prescription drugs to help treat your symptoms, such as steroids to relieve inflammation of the opening of the vagina.
Treatments last one, three, or seven days, all of which are equally effective. Unless you have an allergic reaction to the medication, side effects are generally mild.
Having sex while being treated for a yeast infection is not generally recommended because it may worsen symptoms (by further irritating your vagina) and cause micro-tears in your skin that increase your risk of catching a sexually transmitted disease. (5)
Diflucan (fluconazole) is a prescription pill for yeast infections. Most women only require a single dose of the medication to clear their yeast infection, but fluconazole is not recommended for pregnant women due to a potential risk of harming the developing baby.
Fluconazole may cause mild and infrequent side effects, such as headache, rash, and upset stomach. More rarely, severe side effects may develop, such as flu-like symptoms, swelling, and seizures. (2)
While taking yeast infection medication, certain lifestyle changes can help relieve symptoms and prevent worsening symptoms. These include:
Though azoles work well against C. albicans, some other Candida species are resistant to these first-line drugs.
For example, about half of C. glabrata strains isolated from recurrent yeast infections are far less susceptible to fluconazole than C. albicans, and C. krusei is completely resistant to it.
To treat non-albicans yeast infections, your doctor may prescribe a Mycostatin (nystatin) vaginal cream or tablet, which you must apply or take daily for 14 days.
With treatment, your yeast infection will pass after one to seven days (the length of treatment depends on which product you are using).
If a week is too long for you, you can also try a single dose of a powerful azole oral medication — fluconazole, if appropriate. (7)
Despite the effectiveness of prescription and OTC treatments, some people may choose to try home remedies for yeast infections, including:
But not all home remedies are backed up by clinical trials, and thus have not been proven effective against yeast infections.
Yogurt and supplements containing Lactobacillus — "good" bacteria common in the vagina and elsewhere — are thought to help treat and prevent yeast infections. But evidence for the bacteria's helpfulness is inconsistent. (10)
The same is true for capsules of garlic, which is a natural fungicide. (11)
About 5 to 8 percent of women experience four or more yeast infections in a single year, a condition known as recurrent or chronic yeast infections. (12)
It's not clear why some women get chronic or recurring yeast infections, but there are several risk factors that can predispose you to it, such as pregnancy, birth control pills, estrogen therapy, regular antibiotic use, diabetes, and conditions that affect your immune system, particularly HIV.
Treatments used for normal yeast infections are effective if your recurring yeast infections are caused by C. albicans.
But some infections are caused by other Candida species, such as C. glabrata, which may require treatment with a Mycostatin vaginal cream or tablet, a vaginal gel containing the antifungals amphotericin B and flucytosine, or another treatment.