Pap Smear (Pap Test)

A Pap smear, also called a Pap test, is a test used to detect abnormal cells on the cervix that are cancerous or may become cancerous. The cervix is the lower part of the uterus that connects to the vagina. A Pap smear is conducted by taking a sample of cells from the surface of the cervix during a pelvic exam using a swab or small brush.

A Pap smear is primarily used as a screening test for cervical cancer. Additional health conditions, including infections, inflammation, and other types of cancer may also be detected using this test.

Purpose of the test

A Pap smear identifies abnormal changes in cervical cells. Pap smears have several uses in medical care, including:

• Screening: A Pap smear is most often used to screen for cervical cancer in people without symptoms. It is able to identify cervical cancer early, as well as changes in cervical cells that may become cancerous if not treated. When used as a screening test, a Pap smear may be used alone or along with a test for strains of human papillomavirus (HPV) that can cause cervical cancer.
• Diagnosis: A Pap smear can be used to help determine the underlying cause of vaginal symptoms, including abnormal vaginal bleeding or discharge.
• Monitoring: A Pap smear may be used as a follow-up test to monitor cervical cell abnormalities or other findings detected on an initial Pap smear.

What does the test measure?

A Pap smear involves obtaining a sample of cells from the opening of the cervix and examining them under a microscope for signs of abnormalities. Pap smear results indicate whether cervical cells appear normal, abnormal, or if the test result is unclear. Abnormal Pap smear results are described according to the type of abnormality detected, as well as the type of cell in which the abnormality was found. 

When should I get Pap smear?

Screening for cervical cancer with a Pap test is appropriate for anyone with a cervix, including women and transgender men who have a cervix. When a person with a cervix should get a Pap smear depends on a variety of factors, including age, health, and history of cervical cancer screening. A healthcare practitioner may also order a Pap smear when a patient is pregnant. 

Cervical cancer screening may involve a Pap smear, an HPV test, or cotesting with both tests at the same time. The U.S. Preventive Services Task Force recommends regular cervical cancer screening between ages 21 and 65:

• Ages 21 to 29: Most people with a cervix between 21 and 29 years old should get screened for cervical cancer every three years with a Pap smear alone. 
• Ages 30 to 65: For people with a cervix between 30 and 65 years old, there are several options for cervical cancer screening. Individuals in this age group may choose to be screened every three years with a Pap smear alone, every five years with an HPV test alone, or every five years with both a Pap smear and an HPV test.

Patients should have a discussion with their healthcare provider about the pros and cons of different screening strategies in order to decide which approach is best for their situation.

Patients may need to be screened for cervical cancer more often if they have one of the following risk factors:

• A history of abnormal Pap smears
• HIV
• A mother who was exposed to diethylstilbestrol (DES) while pregnant
• A weakened immune system

Other groups do not need regular cervical cancer screening. These groups include:

• Patients who are under 21 years of age
• Patients who are older than 65, have had adequate screening in the past, and are not at an increased risk of cervical cancer
• People who have had a hysterectomy and who do not have a history of abnormal Pap smears or cervical cancer

How to get tested

A Pap smear is generally ordered by a doctor and conducted in a medical setting such as a doctor’s office or health clinic. Analysis of the sample of cervical cells is performed in a medical laboratory. 

Can I take the test at home?

At-home Pap smears are not currently used in the United States. Patients who are interested in at-home screening tests for cervical cancer may find it helpful to discuss at-home HPV testing with their doctor.

How much does the test cost?

The cost of a Pap smear depends on where the test is taken and if you have insurance coverage. Costs of testing may include the office visit, the fee for the healthcare professional to conduct the Pap smear, and the actual laboratory analysis. 

If your doctor recommends a Pap smear, these costs are typically covered by insurance, but, depending on your plan, you may be responsible for copays or a deductible. Your doctor and insurance plan can provide more specific information about your costs for a Pap smear. Local and federal health departments may offer financial assistance programs for Pap smears for people who don’t have insurance.

A Pap smear requires a sample of cells from the opening of the cervix. These cells are obtained by gently scraping the cervix with a swab or small brush.

Before the test

Before a Pap smear, it’s important to tell your doctor about any medications you are taking, if you’ve had an abnormal Pap smear in the past, or if you might be pregnant. You should not have a Pap smear while you are menstruating, so it’s best to schedule this test around five days after the last day of your period.

Additional pre-test precautions include avoiding the following activities within two to three days before a Pap smear:

• Using tampons
• Having sex
• Douching
• Using vaginal creams or birth control foams 

You may feel more comfortable if you empty your bladder right before a Pap smear.

During the test

A Pap smear may be conducted during a pelvic examination. A pelvic examination involves lying on an exam table with your feet in stirrups while a health care provider examines your vulva, vagina, cervix, rectum, and pelvis.

During the Pap smear, an instrument called a speculum is gently inserted into your vagina, allowing the health care provider to see the cervix. Once the provider can see the cervix, they obtain a small sample of cells by gently scraping the cervix with a brush, spatula, or scraper. This portion of the Pap smear only takes a few seconds.

Most patients experience little to no pain or discomfort during a Pap smear. Some may experience a feeling of pressure or temporary cramping similar to menstrual cramps. 

After the test

While you may experience vaginal bleeding for a short time after a Pap smear, there are no restrictions on activities after a Pap smear is complete.

Receiving test results

The results of a Pap smear are most often available within one to three weeks. Results may be sent to the patient electronically or by mail. A doctor’s office may also contact the patient to discuss Pap smear results or to arrange a follow-up appointment.

Interpreting test results

Pap smear results are reported as normal, abnormal, or unsatisfactory for evaluation. A normal, also called negative, Pap smear result indicates that no evidence of abnormal cells were found in the sample. An abnormal, or positive, result on a Pap smear indicates that abnormal cells were detected in the sample and additional treatment or testing may be necessary. Treatment of abnormal cervical cells prevents the development of cervical cancer.

Cell types commonly described in Pap smear results include squamous and glandular cells. Squamous cells are a type of cell that lines the outer portion of the cervix. Abnormal changes in squamous cells are divided into several categories:

• Atypical squamous cells (ASC): Atypical squamous cells are the most common abnormal finding on a Pap smear. Atypical squamous cells may be reported as atypical squamous cells of undetermined significance (ASC-US) or atypical squamous cells, cannot exclude a high-grade squamous intraepithelial lesion (ASC-H). Both results indicate that cervical cells appear abnormal under the microscope, but the meaning of the cell changes is unclear. A result of ASC-H indicates that cells may be at a higher risk of becoming cancerous than a result of ASC-US.
• Low-grade squamous intraepithelial lesions (LSIL): Sometimes called mild dysplasia, a result of LSIL indicates that the Pap smear detected mild cell changes. A result of LSIL may not require treatment, as these changes are often resolved by the immune system, especially in younger people.
• High-grade squamous intraepithelial lesions (HSIL): Sometimes called moderate or severe dysplasia, an HSIL finding indicates that somewhat to very abnormal cell changes were detected. These changes are more likely than LSILs to progress into cancer if left untreated.
• Carcinoma in situ (CIS): A result of CIS indicates that more severe cell changes were found during the Pap smear. These changes appear similar to cervical cancer, but have not yet spread beyond the surface of the cervix. CIS is likely to progress into cancer if left untreated.
• Squamous cell carcinoma: Squamous cell carcinoma is a type of cervical cancer. Finding squamous cell carcinoma on a Pap smear is very rare for patients who receive regular cervical cancer screening. This result indicates that abnormal squamous cells have spread more deeply into the cervix or to other parts of the body.

Glandular cells are found in the tissue that lines the inner portion of the cervix. Abnormal cell changes in glandular cells are divided into the following categories:

• Atypical glandular cells (AGC): A result of AGC indicates that abnormal glandular cells were seen under the microscope, but the meaning of these cell changes is unclear. 
• Endocervical adenocarcinoma in situ (AIS): This result means that more severe cell changes were found but have not yet spread beyond the glandular tissue of the cervix. 
• Adenocarcinoma: Adenocarcinoma is a type of cervical cancer that begins in glandular cells. While very rarely found on Pap tests in people who are regularly screened for cervical cancer, a result of adenocarcinoma indicates that abnormal glandular cells have spread more deeply into the cervix or to other parts of the body.

In addition to detecting the presence of cell changes in squamous and glandular tissue, a Pap smear may also detect several other kinds of abnormalities:

• Endometrial cells: A Pap smear may detect endometrial cells, which are cells from the lining of the uterus. While these cells may be present in healthy individuals during menstruation, they should not be present in a cervical sample after menopause. Because this finding may be normal in young patients, endometrial cells are only reported in Pap smear results for patients 45 and older. 
• Other types of cancer: Although not the primary goal of a Pap smear, this test can sometimes detect cancerous cells not related to cervical cancer. A Pap smear may detect cancerous cells from the fallopian tubes, ovaries, endometrium, peritoneum, vulva, or vagina.
• Infection or inflammation: A Pap test may detect evidence of infections and inflammation of the cervix.

Unsatisfactory results on a Pap smear indicate that the sample of cervical cells obtained for the test either didn’t have enough cells on the slide to be examined or the quality of the slide wasn’t satisfactory. Unsatisfactory results may be followed up by a repeat Pap smear.

Are test results accurate?

A Pap smear is not 100% accurate. Abnormal cells may be missed in some individuals. Fortunately, cervical cancer typically develops slowly and it can take years, or even decades, for abnormal cells to develop into cervical cancer. Because cell changes progress slowly, regular Pap smears can usually detect cell changes before they progress into cervical cancer.

Do I need follow-up tests?

Follow-up testing after a Pap smear will depend on the test results and a patient’s reason for being tested. For individuals undergoing screening for cervical cancer who have a normal Pap smear result, it’s important to continue cancer screening at regular intervals. 

People who receive abnormal Pap smear results require follow-up tests and/or treatment in order to further assess the cervix for signs of disease. For minor abnormalities such as ASC-US, a doctor may recommend a human papillomavirus (HPV) test and/or having another Pap smear in a year to see if the abnormality resolves without treatment.

For a result of LSIL, a doctor may recommend additional testing to look for more serious abnormalities on another portion of the cervix.

If a patient has more severe abnormalities, including ASC-H or HSIL a doctor may recommend a colposcopy. A colposcopy is a procedure that involves the use of an instrument called a colposcope to more closely examine the cervix. Doctors may perform a biopsy during a colposcopy to remove additional tissue for examination.

Questions for your doctor about test results

Your doctor can address detailed and specific questions about your Pap smear results. Some questions that you might review with your doctor include: 

• Was any part of my Pap smear result abnormal? 
• If there was an abnormal Pap smear result, can you explain what was found and what it may mean? 
• If Pap smear results were normal, when should I have this testing again in the future? 
• Are there any follow-up tests that may be beneficial given my test result?

How is a Pap smear different from an HPV test?

The human papillomavirus (HPV) test is used to detect infections with high-risk types of HPV that can cause abnormal changes in cervical cells. An HPV test may be used to screen for cervical cancer alone, in combination with a Pap smear, or to follow up on an abnormal Pap smear result.

Other related tests

• Human Papillomavirus (HPV) Test
• STD Testing

These resources provide additional information about cervical cancer and screening tests: 

• American College of Obstetricians and Gynecologists: Abnormal Cervical Cancer Screening Test Results
• CDC: Cervical Cancer
• CDC: What Do My Cervical Cancer Screening Test Results Mean?
• National Cancer Institute: Cervical Cancer Screening
• National Cancer Institute: Understanding HPV and Pap Test Results

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