Yeast Infection Test

What is a Yeast Infection Test?

A yeast infection test is used to diagnose and detect yeast infections. There are different methods of yeast testing, depending on where you have symptoms.

Yeast is a type of fungus that can live on the skin, mouth, digestive tract, and genitals. Some yeast in the body is normal, but if there is an overgrowth of yeast on your skin or other areas, it can cause an infection. A yeast test can help determine whether you have a yeast infection. Candidiasis is another name for a yeast infection.

Other names

Potassium hydroxide preparation, fungal culture; fungal antigen and antibody tests, calcofluor white stain, fungal smear

Why do I need a yeast test?

Your health care provider may order a test if you have symptoms of a yeast infection. Your symptoms will vary, depending on where the infection is on your body. Yeast infections tend to happen in moist areas of the skin and mucous membranes. Below are symptoms of some common types of yeast infections. Your individual symptoms may vary.

Yeast infections on the folds of the skin include conditions such as athlete’s foot and diaper rash. Symptoms include:

Bright red rash, often redness or ulcers in the skin
Itching
Burning sensation
Pimples

Yeast infections on the vagina are common. Nearly 75% of women will get at least one yeast infection in their lifetime. Symptoms include:

Genital itching and/or burning
A white, cottage cheese-like discharge
Painful urination
Redness in the vagina

Yeast infection of the penis may cause:

Redness
Scaling
Rash

Yeast infection of the mouth is called thrush. It is common in young children. Thrush in adults may indicate a weakened immune system. Symptoms include:

White patches on the tongue and inside of cheeks
Soreness on the tongue and inside of cheeks

Yeast infection at the corners of the mouth may be caused by thumb sucking, ill-fitting dentures, or frequent licking of the lips. Symptoms include:

Cracks and tiny cuts at the corners of the mouth

Yeast infection in the nail beds can happen in the fingers or toes, but are more common in toenails. Symptoms include:

Pain and redness around the nail
Discoloration of nail
Cracks in the nail
Swelling
Pus
White or yellow nail that separates from nail bed

What happens during a yeast test?

The type of test depends on the location of your symptoms.

If a vaginal yeast infection is suspected, your health care provider will perform a pelvic exam and take a sample of the discharge from your vagina.
When thrush is suspected, your health care provider will look at the infected area in the mouth and may also take a small scraping to examine under the microscope.
If a yeast infection is suspected on the skin or nails, your health care provider may use a blunt-edged instrument to scrape off a small bit of skin or part of a nail for examination. During this type of test, you may feel some pressure and a little discomfort.

Your health care provider may be able to tell if you have a yeast infection just by examining the infected area and looking at the cells under a microscope. If there are not enough cells to detect an infection, you may need a culture test. During a culture test, the cells in your sample will be put in a special environment in a lab to encourage cell growth. Results are often available within a few days. But some yeast infections grow slowly, and it may take weeks to get a result.

Will I need to do anything to prepare for the test?

You don’t need any special preparations for a yeast test.

Are there any risks to the test?

There is no known risk to having a yeast test.

What do the results mean?

If your results indicate a yeast infection, your health care provider may recommend an over-the-counter antifungal medicine or prescribe an antifungal medicine. Depending on where your infection is, you may need a vaginal suppository, a medicine applied directly to the skin, or a pill. Your health care provider will tell you which treatment is best for you.

It’s important to take all your medicine as prescribed, even if you feel better sooner. Many yeast infections get better after a few days or weeks of treatment, but certain fungal infections may need to be treated for several months or longer before they clear up.

Is there anything else I need to know about a yeast test?

Certain antibiotics can also cause an overgrowth of yeast. Be sure to tell your health care provider about any medicines you are taking.

Yeast infections of the blood, heart, and brain are less common but more serious than yeast infections of the skin and genitals. Serious yeast infections occur more often in hospital patients and in people with weakened immune systems.

References

Centers for Disease Control and Prevention [Internet]. Atlanta: U.S. Department of Health and Human Services; Candidiasis; [updated 2016 Oct 6; cited 2017 Feb 14]; [about 6 screens]. Available from: https://www.cdc.gov/fungal/diseases/candidiasis/
Centers for Disease Control and Prevention [Internet]. Atlanta: U.S. Department of Health and Human Services; Fungal Nail Infections; [updated 2017 Jan 25; cited 2017 Feb 14]; [about 9 screens]. Available from: https://www.cdc.gov/fungal/nail-infections.html
Centers for Disease Control and Prevention [Internet]. Atlanta: U.S. Department of Health and Human Services; Invasive Candidiasis; [updated 2015 Jun 12; cited 2017 Feb 14]; [about 8 screens]. Available from: https://www.cdc.gov/fungal/diseases/candidiasis/invasive/index.html
Centers for Disease Control and Prevention [Internet]. Atlanta: U.S. Department of Health and Human Services; Oropharyngeal /Esophageal Candidiasis (“Thrush”); [updated 2014 Feb 13; cited 2017 Apr 28]; [about 5 screens]. Available from: https://www.cdc.gov/fungal/diseases/candidiasis/thrush/
Hinkle J, Cheever K. Brunner & Suddarth’s Handbook of Laboratory and Diagnostic Tests. 2^nd Ed, Kindle. Philadelphia: Wolters Kluwer Health, Lippincott Williams & Wilkins; c2014. Candida Antibodies; p. 122 Lab Tests Online [Internet]. Washington D.C: American Association for Clinical Chemistry; c2001–2019. Fungal Tests; [updated 2018 Dec 21; cited 2019 Apr 1]; [about 2 screens]. Available from: https://labtestsonline.org/tests/fungal-tests
Lab Tests Online [Internet]. American Association for Clinical Chemistry; c2001–2017. Fungal Tests: The Test; [updated 2016 Oct 4; cited 2017 Feb 14]; [about 4 screens]. Available from: https://labtestsonline.org/understanding/analytes/fungal/tab/test/
Lab Tests Online [Internet]. American Association for Clinical Chemistry; c2001–2017. Fungal Tests: The Test Sample; [updated 2016 Oct 4; cited 2017 Feb 14]; [about 3 screens]. Available from: https://labtestsonline.org/understanding/analytes/fungal/tab/sample/
Lab Tests Online [Internet]. American Association for Clinical Chemistry; c2001–2017. Glossary: Culture; [cited 2017 Apr 28]; [about 3 screens]. Available from: https://labtestsonline.org/glossary/culture
Mayo Clinic [Internet]. Mayo Foundation for Medical Education and Research; c1998–2017. Oral Thrush: Tests and diagnosis; 2014 Aug 12 [cited 2017 Apr 28]; [about 7 screens]. Available from: http://www.mayoclinic.org/diseases-conditions/oral-thrush/basics/tests-diagnosis/con-20022381
Merck Manual Consumer Version [Internet]. Kenilworth (NJ): Merck & Co., Inc.; c2016. Candidiasis; [cited 2017 Feb 14]; [about 4 screens]. Available from: http://www.merckmanuals.com/home/infections/fungal-infections/candidiasis
Merck Manual Consumer Version [Internet]. Kenilworth (NJ): Merck & Co., Inc.; c2016. Candidiasis (Yeast Infection); [cited 2017 Feb 14]; [about 4 screens]. Available from: http://www.merckmanuals.com/home/skin-disorders/fungal-skin-infections/candidiasis-yeast-infection
Mount Sinai [Internet]. Icahn School of Medicine at Mount Sinai; c2017. Skin Lesion KOH Exam; 2015 Apr 4 [cited 2017 Feb 14]; [about 3 screens]. Available from: https://www.mountsinai.org/health-library/tests/skin-lesion-koh-exam
University of Rochester Medical Center [Internet]. Rochester (NY): University of Rochester Medical Center; c2017. Health Encyclopedia: Microscopic Yeast Infection; [cited 2017 Feb 14]; [about 2 screens]. Available from: https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=85&contentid;=P00265
WomensHealth.gov [Internet]. Washington DC: Office on Women’s Health, U.S. Department of Health and Human Services; Vaginal yeast infection; [updated 2015 Jan 6; cited 2017 Feb 14]; [about 4 screens]. Available from: https://www.womenshealth.gov/publications/our-publications/fact-sheet/vaginal-yeast-infections.html