Yeast Infections (Candidiasis)

According to the Centers for Disease Control (CDC), about 75% of women get at least one yeast infection during their lifetime and 40-45% will have two or more. Some women have many yeast infections. Women of all ages can get yeast infections.

What causes yeast infections?

Yeast infections are usually caused by an overgrowth of a type of fungus called Candida, also known as yeast. Small amounts of yeast and other organisms are normally found in your vagina, as well as in your mouth and digestive tract. Yeast infections occur when the balance of organisms in your vagina is upset, and the amount of yeast grows too much, causing an infection. Yeast infections are most likely to be noticeable just before or just after your menstrual period. Some types of “yeast” infections are harder to treat and are caused by other species. Ask your health care provider (HCP) if you should be checked for the other types if your symptoms do not get better.

This balance of organisms in your vagina can be changed by:

• Antibiotics (for acne, throat, ear infections, or even other kinds of vaginal infections) because they can kill the normal bacteria in your vagina and let the yeast grow
• Being overweight
• Diabetes
• Pregnancy
• HIV infection
• Steroids
• Birth control pills and other contraceptives
• Tight underwear made of material such as nylon or Lycra that traps moisture and heat, especially in the summer. (Cotton underwear is a good choice because it absorbs moisture better.)

What are the signs/symptoms of a yeast infection?

The most common symptoms of a yeast infection are itching and vaginal discharge. The discharge is often thick, white, and curd-like (almost like cottage cheese). The discharge will be odorless. Other signs are burning, redness, and irritation of the vaginal area. Severe yeast infections may cause swelling of the labia (lips) outside of the vagina. Sometimes, women have pain when they pee as the urine passes over the sore tissues.

Sexual intercourse may also be painful for you because of inflammation of the vagina.

How are yeast infections diagnosed?

A health care provider will use a cotton swab to take a sample of your vaginal discharge. The sample is put on a slide along with a drop of a special liquid. Your health care provider or a person working in a lab will then look at the sample under a microscope to see if you have an overgrowth of yeast. There are other office-based tests for evaluating vaginal discharge. Your health care provider may also do a culture of the discharge, particularly if you have had yeast infections that keep coming back.

How are yeast infections treated?

Yeast infections are treated with a pill that you swallow, or with a vaginal cream or vaginal suppository (a partially solid material that you insert into your vagina, where it dissolves and releases medicine). Your health care provider will explain to you what your choices are and if one is better than another for you. The pill is especially good if you don’t want to put cream inside of your vagina. Some anti-yeast vaginal creams are sold over the counter (without a prescription) in pharmacies. Other anti-yeast vaginal creams need a prescription. If you use a cream, then you should not use tampons during the treatment since it will absorb the medication and make it less effective.

Some anti-yeast vaginal medications that are oil-based may weaken latex condoms making them more likely to break. Talk to your health care provider about whether you should use a polyurethane condom or not have sex.

Remember: Do not use anti-yeast medications without seeing your health care provider, unless you’ve been diagnosed by an HCP more than once, so you’re sure of the symptoms and signs. The medicine(s) that is prescribed for yeast infections will not cure other kinds of vaginal infections such as bacterial vaginosis or sexually transmitted infections (STIs). You would need another prescription medicine to treat the infection.

Can yeast infections cause serious problems?

Yeast infections are not known to cause any serious health problems. However, the yeast infection itself can be very unpleasant, so you should get diagnosed and treated as soon as possible.

Is there anything else I can do to prevent yeast infections?

You can lower your risk of getting a yeast infection by:

• Never using vaginal douche products
• Wearing cotton underwear and loose-fitting pants
• Changing out of a wet bathing suit or tight workout clothes as soon as you can
• Taking antibiotics only when your health care provider feels you need

If you have to take antibiotics and are getting lots of yeast infections, talk to your health care provider about using an anti-yeast cream or pill.

What if I get yeast infections all the time?

Some women get yeast infections every month around the time of their menstrual periods. Your health care provider may tell you that you need to take medicine every month to prevent yeast infections. This is done to stop the symptoms from developing, or if you get a lot of infections, you may be told that you need to take oral pills for up to 6 months. Never self-treat unless you’ve talked to your health care provider.

Our health guides are developed through a systematic, rigorous process to ensure accuracy, reliability, and trustworthiness. Written and reviewed by experienced healthcare clinicians from Boston Children's Hospital, a Harvard Medical School teaching hospital and consistently ranked as a top hospital by Newsweek and U.S. News & World Report, these guides combine clinical expertise, specialized knowledge, and evidence-based medicine. We also incorporate research and best practices from authoritative sources such as the CDC, NIH, PubMed, top medical journals, and UpToDate.com. Clinical specialists and subject matter experts review and edit each guide, reinforcing our commitment to high-quality, factual, scientifically accurate health information for young people.