Yeast Infection Tests

A yeast test can help find out whether you have a yeast infection. Candidiasis, candidosis, and moniliasis are other names for a yeast infection. Yeast is a type of fungus.

Fungi (more than one fungus) are plant-like life forms that live everywhere, including on your skin, genitals, mouth, and intestines (gut). Usually, yeast doesn't make you sick. But if yeast grows out of control, it can cause an infection that needs treatment.

If you're generally healthy, a yeast infection is rarely serious. But for some people, a yeast infection may become very serious. It may affect the blood, heart, brain, eyes, bones, or other parts of your body.

This is called an invasive yeast infection. Invasive infections are usually not a risk for healthy people. But you may be at higher risk of an invasive infection, for example if you have a weakened immune system or a central venous catheter, or if you've had surgery or chemotherapy.

Why this test is done

Your health care provider may order a test if you have symptoms of a yeast infection. Symptoms depend on where the yeast is growing. Yeast infections tend to grow in moist areas of your skin and mucous membranes.

These are the typical symptoms of some common types of yeast infections, but your symptoms may vary:

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

• Bright red rash, often with ulcers (open sores)
• Itching and/or burning
• Pimples

Vaginal yeast infections are very common. Symptoms include:

• Itching and/or burning in your vagina and vulva (the external female genital organs)
• A white discharge that looks like cottage cheese
• Pain when urinating (peeing) and during sex
• Redness and swelling of your vagina and labia (folds of skin around the vagina)

Yeast infection of the penis is more common if you have diabetes or a foreskin (you are not circumcised). Symptoms include:

• Redness
• Itching and/or burning
• Rash on the head of the penis that may be painful

Yeast infection of the mouth is called thrush. It is common in young children. Thrush in adults may be a sign of a weakened immune system.

Symptoms include:

• White patches on the:
• Tongue
• Inside of cheeks
• Roof of the mouth
• Throat
• Redness or soreness
• Cotton-like feeling in the mouth
• Loss of taste
• Pain while eating

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 redness at the corners of the mouth

Yeast infection in the nail beds can happen in the fingernails or toenails, but it's more common in toenails. Symptoms include:

• Discolored nail (yellow, brown, or white)
• Thick nail
• Cracks in the nail
• Pain and redness if the infection is severe

How to prepare

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

Other names for this test

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