An abnormal Pap smear means that some cells collected from your cervix looked different from normal under a microscope. Nearly 4% of all Pap tests come back flagged as abnormal, and the vast majority of those do not indicate cancer. Most reflect minor cell changes caused by HPV infection, hormonal shifts, or even something as routine as a yeast infection.
What matters most is the specific type of abnormality found, because that determines what happens next. The range spans from barely-worth-watching changes to cells that need prompt attention.
Types of Abnormal Results
Your Pap result will use one of several standardized terms. Each one describes how abnormal the cells look and where they came from on the cervix.
ASC-US (atypical squamous cells of undetermined significance) is the most common abnormal finding. It means some cells don’t look completely normal, but the changes are so mild that it’s unclear whether HPV or something else caused them. Irritation, yeast infections, uterine polyps, and hormonal changes from pregnancy or menopause can all produce ASC-US results without any underlying disease.
LSIL (low-grade squamous intraepithelial lesion) indicates mildly abnormal cells, usually caused by an HPV infection that often clears on its own without treatment. Think of LSIL as a step above ASC-US: the changes are more clearly defined, but they’re still considered low-grade.
ASC-H (atypical squamous cells, cannot exclude high-grade lesion) is a less common finding that sits in an uncertain zone. The cells look abnormal enough that a more serious problem can’t be ruled out from the Pap alone, so further evaluation is always recommended.
HSIL (high-grade squamous intraepithelial lesion) indicates more serious changes. HSIL is more likely than the categories above to be linked to precancerous cells or, less commonly, cancer. It requires prompt follow-up.
AGC (atypical glandular cells) means changes were found in a different type of cervical cell, the glandular cells that line the inner canal of the cervix and uterus. AGC raises concern for precancer or cancer and follows its own set of guidelines because it carries a disproportionately higher risk compared to most squamous cell abnormalities.
Why HPV Testing Matters
Most abnormal Pap results are driven by HPV, the human papillomavirus. That’s why many screening programs now test for HPV at the same time as the Pap (called co-testing). Your HPV result dramatically changes what your abnormal Pap actually means in practice.
If you have ASC-US but test negative for HPV, your risk of having a serious underlying problem is very low. In that scenario, you’ll likely just repeat screening in a few years. If you have ASC-US and test positive for HPV, especially for the higher-risk strains HPV-16 or HPV-18, your provider will want closer follow-up. Current guidelines use a risk-based approach: they estimate your personal likelihood of having or developing serious precancerous changes and match your follow-up plan to that risk level.
What Happens After an Abnormal Result
Your next steps depend on how abnormal the cells looked and your HPV status. There are three general paths.
Repeat testing in one to three years. For low-risk findings, like ASC-US with a negative HPV test, guidelines recommend repeating your screening at one-year or three-year intervals depending on your estimated risk. If your chance of developing serious precancerous changes is below about 0.55% over five years, a three-year follow-up is typical. If it’s somewhat higher but still under 4%, you’ll repeat in one year. When HPV testing isn’t available and only Pap results are used, repeat cytology may be recommended at six-month intervals instead.
Colposcopy. When your immediate risk of having serious precancerous changes reaches 4% or higher, your provider will recommend a colposcopy. This is an in-office procedure where a magnifying instrument is positioned just outside your body to give a close-up, illuminated view of your cervix. You lie back as you would for a regular pelvic exam, a speculum holds the vaginal walls open, and a mild solution is dabbed on the cervix with a cotton swab. This solution makes abnormal areas stand out visually. The whole thing feels similar to a Pap test, though some people notice a slight burning from the solution. If the provider spots abnormal-looking tissue, they’ll take a small biopsy, a tiny sample snipped from the cervix, to send to the lab for a definitive diagnosis.
For the most accurate results, you should avoid using tampons, vaginal medications, douching, or having sex for at least 24 hours before a colposcopy, and the procedure is best done when you’re not on your period.
Treatment. If a biopsy confirms high-grade precancerous cells, the goal is to remove them before they can progress to cancer. The most common approach is called a LEEP, where a small electrified wire loop shaves away a thin layer of abnormal tissue from the cervix. It’s done in a clinic or office setting and is effective at stopping precancerous cells from developing further. Cryotherapy, which freezes abnormal tissue, is another option in some cases. After treatment, you’ll have more frequent follow-up screenings for several years to make sure the abnormal cells don’t return.
Common Causes That Aren’t Cancer
The list of things that can make cervical cells look abnormal is long, and most of them are harmless. HPV infection is the leading cause, and most HPV infections, particularly in younger people, resolve on their own within one to two years without ever causing precancer. Beyond HPV, vaginal yeast infections, bacterial infections, cervical polyps, general irritation, and the hormonal changes of pregnancy or menopause can all trigger an abnormal Pap result.
This is exactly why an abnormal Pap isn’t a diagnosis. It’s a screening flag that tells your provider something needs a closer look. The follow-up testing, whether that’s a repeat Pap, HPV test, or colposcopy, is what actually determines whether there’s a real problem.
How Risk-Based Guidelines Work
Current management guidelines don’t treat every abnormal result the same way. Instead, they calculate your individual risk of having or developing serious precancerous changes based on a combination of your Pap result, your HPV status, and your screening history. The core principle is that people with the same level of risk get the same management, regardless of which specific combination of results got them there.
For most abnormal findings, this risk-based system means fewer unnecessary procedures for low-risk people and faster action for high-risk ones. Certain results, though, bypass the standard risk calculator entirely because they carry outsized risk. These include AGC (glandular cell abnormalities), ASC-H, and cases where HPV-16 or HPV-18 are detected alongside normal-looking cells. If you receive any of these results, your provider will typically move directly to colposcopy rather than waiting to repeat screening.