How does a yeast infection affect Pap smear test results?

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A Pap smear samples cells from the cervix to look for any changes caused by human papillomavirus (HPV) that can lead to cervical cancer if left untreated.

According to the National Cancer Institute (NCI), yeast infections can lead to an abnormal Pap smear finding called atypical squamous cells of undetermined significance (ASC-US).

ASC-US is the most common abnormal Pap smear result. It means that some of the cells do not appear normal and it is not clear if HPV is the cause.

Do yeast infections cause abnormal cells?

A yeast infection does not cause abnormal cells. However, it can cause some cells to appear abnormal.

It is important to note that the abnormal appearance of these cells is not related to cancer.

If a person has symptoms of a yeast infection, or is taking medications for a yeast infection, they should inform the doctor before the Pap smear appointment.

The doctor may suggest that they rearrange the Pap smear until a person has finished treating the yeast infection.

In some cases, a yeast infection may not cause any symptoms, so a person may not know they have it. In this case, the Pap smear result may come back as ASC-US.

If this happens, the NCI states that the doctor may perform an HPV test if they did not do this previously to determine if the abnormal result is due to HPV.

Learn more about treating a yeast infection here.

Vaginitis refers to the inflammation of the vagina that can occur due to a disruption of the vaginal microbiome. A yeast infection is a type of vaginitis.

According to an older 2011 study, the risk of developing vaginitis may rise slightly in the 7 weeks following a Pap smear test.

This may happen due to the use of lubricant and the speculum, which could alter the balance of vaginal organisms. However, more research is necessary to establish a definite risk.

The NCI states that the following can cause abnormal Pap smear results:

• vaginal irritation
• growths, such as polyps in the uterus
• hormonal changes that occur during menopause or pregnancy

The Centers for Disease Control and Prevention (CDC) recommend avoiding the following before a Pap smear:

• douching
• using a tampon
• sexual activity
• birth control jelly, foam, or cream
• medications in the vagina

Pap smear results may return one of several results:

• Normal: There is no sign of cancer, pre-cancer, or other abnormalities.
• Unsatisfactory Pap test results: There may not have been enough of a sample, or there may have been blood or mucus hiding the cells. A healthcare professional will request a second screening within 2–4 months.
• Abnormal: There are changes to the cervical cells. It is important to note that this does not mean a person has cancer. Abnormal results include:
  • ASC-US
  • atypical glandular cells (AGC), which means that there were some abnormal glandular cells
  • low-grade squamous intraepithelial lesions (LSIL), which usually means that HPV has caused low-grade changes
  • high-grade squamous intraepithelial lesions (HSIL), which means that moderately or severely abnormal cervical cells were present
  • atypical squamous cells, cannot exclude HSIL (ASC-H), which means that abnormal cells were present that could be HSIL
  • adenocarcinoma in situ (AIS), which means there is an advanced area of abnormal growth on the cervix
  • cervical cancer cells

Learn more about Pap smears and when to have one here.

A yeast infection can cause some cells to appear abnormal, which means that the results of a Pap smear come back as ASC-US. However, this is not an indication of cervical cancer.

There may also be a slight increased risk of a person developing a yeast infection following a Pap smear due to the introduction of the speculum and lubricant to the vaginal microbiome.

If a person has a yeast infection when they are due a Pap smear, they should contact the doctor to discuss rearranging the appointment.