A Pap smear is a screening test that collects cells from your cervix and examines them under a microscope for early signs of cervical cancer. The test doesn’t diagnose cancer directly. Instead, it detects abnormal cell changes, called precancerous cells, that could develop into cancer years down the line if left untreated. It can also pick up certain infections and inflammation.
How the Test Works
The Pap smear is a quick office procedure, typically lasting just a few minutes. You lie on an exam table, and your provider inserts a speculum (a plastic or metal instrument) into the vagina to hold the walls apart and get a clear view of the cervix. Then they use a soft brush and a flat scraping tool called a spatula to gently collect cells from the surface of the cervix and the area around it. Those cells go into a small bottle with a preserving solution and are sent to a lab, where a technician examines them under a microscope.
Most people describe the sensation as brief pressure or mild discomfort rather than pain. The whole collection process takes under a minute. Results typically come back within one to three weeks, depending on the lab.
How to Prepare
For the most accurate results, avoid intercourse, douching, and any vaginal medicines, spermicidal foams, creams, or jellies for two days before your appointment. These can wash away or obscure the cervical cells the test needs to evaluate. If your period starts on the day of your test, it’s usually best to reschedule, since blood can interfere with the sample.
When and How Often You Need One
Screening guidelines from the U.S. Preventive Services Task Force break down by age:
- Under 21: No screening recommended, regardless of sexual activity.
- Ages 21 to 29: A Pap smear every 3 years.
- Ages 30 to 65: A Pap smear every 3 years, an HPV test alone every 5 years, or both tests together (co-testing) every 5 years.
- Over 65: No further screening if you’ve had adequate prior results and aren’t at high risk.
- After hysterectomy: No screening needed if your cervix was removed and you have no history of high-grade precancerous lesions or cervical cancer.
These are baseline recommendations. Your provider may suggest a different schedule if you have risk factors like a compromised immune system or a history of abnormal results.
Pap Smear vs. HPV Test
These two tests are related but look for different things. A Pap smear examines the cells themselves for visible abnormalities. An HPV test checks for the presence of high-risk strains of human papillomavirus, the virus responsible for nearly all cervical cancers. Think of it this way: the HPV test looks for the cause, while the Pap smear looks for the effect.
Neither test is perfect on its own. A single Pap smear catches high-grade precancerous lesions about 55% to 80% of the time. When used to detect more advanced abnormalities specifically, sensitivity ranges from 70% to 80% with a specificity around 95%, meaning false positives are uncommon at that threshold. Co-testing with HPV improves overall detection, which is why guidelines offer it as an option for people 30 and older.
Understanding Your Results
A normal result (sometimes called “negative”) means no abnormal cells were found. You follow your regular screening schedule and come back in 3 or 5 years depending on your age and testing method.
An abnormal result does not mean you have cancer. It means some cells looked unusual, and the lab categorizes them by severity:
- Minor abnormalities (ASC-US): Cells that look slightly unusual but don’t clearly fit into a specific category. This is the most common abnormal result and is often caused by temporary factors like inflammation or a low-risk HPV infection. The typical next step is an HPV test or a repeat Pap in one year.
- Low-grade changes (LSIL): Mildly abnormal cells, frequently linked to an HPV infection. These often resolve on their own, especially in younger patients, but your provider will monitor them more closely.
- High-grade changes (HSIL): More significantly abnormal cells with a higher chance of progressing to cancer if untreated. This result usually leads to further evaluation or treatment relatively quickly.
- Atypical glandular cells: Unusual cells from the glandular lining of the cervix or uterus. These are less common but typically prompt a more thorough workup because they can sometimes indicate more serious changes.
What Happens After an Abnormal Result
Your next steps depend on your specific result, your HPV status, your age, and your screening history. Current guidelines use a risk-based approach: your provider calculates the estimated chance that a serious precancerous lesion is present, then matches that risk level to a recommended action.
For lower-risk results, that action might simply be repeating the test in one to three years. For moderate-risk results, you’ll likely be referred for a colposcopy, a procedure where a provider uses a magnifying instrument to get a close-up view of the cervix and may take a small tissue sample (biopsy) for closer analysis. For the highest-risk combinations, such as high-grade cell changes with a positive HPV 16 result, treatment without a preceding biopsy may be recommended to avoid delays.
The key thing to understand is that the system is designed to catch problems years before they would ever become cancer. Cervical cancer develops slowly, and abnormal cells detected on a Pap smear are typically very treatable. Even a high-grade result, when caught through screening, almost always leads to a straightforward outpatient treatment that removes the abnormal tissue and prevents progression.