An abnormal Pap smear means some cells collected from your cervix looked different from normal under a microscope. In most cases, this does not mean you have cancer. The majority of abnormal results reflect minor cell changes, often caused by a common viral infection called HPV, and many of these changes resolve on their own without treatment.
What matters is the specific type of abnormality found, because that determines what happens next. Your results will fall into one of several categories, ranging from barely unusual cells to more concerning changes that need closer attention.
Types of Abnormal Results
Your Pap result will use specific medical terms that describe how abnormal the cells look and where they came from. Here’s what each one means in plain language.
ASC-US (atypical squamous cells of undetermined significance) is the most common abnormal finding. It means some cells look slightly off, but it’s not clear why. The changes might be from an HPV infection, or they could be from something as routine as inflammation or hormonal shifts. This is the mildest category, and many ASC-US results return to normal without any intervention.
LSIL (low-grade squamous intraepithelial lesion) means there are low-grade cell changes, usually caused by HPV. “Low-grade” means the cells are only mildly abnormal. Your immune system clears most HPV infections within a year or two, and these cell changes often go away on their own as that happens.
HSIL (high-grade squamous intraepithelial lesion) is more serious. It means there are moderately or severely abnormal cells that could develop into cervical cancer over time if left untreated. HSIL does not mean cancer is present right now, but it does require prompt follow-up and often treatment.
AGC (atypical glandular cells) means some of the glandular cells in your cervix don’t look normal. Glandular cells line the inner canal of the cervix and the inside of the uterus, so this finding can sometimes point to a problem higher up in the reproductive tract. AGC typically leads to a more thorough evaluation.
Why Cells Change in the First Place
HPV is the most common driver of abnormal Pap results. It’s an extremely widespread virus, and most people who are sexually active will contract it at some point. In the vast majority of cases, the immune system eliminates the infection within one to two years and the cervical cells return to normal. But when the immune system can’t clear a high-risk strain of HPV, the infection can persist for years, gradually turning normal cervical cells into abnormal ones. Without treatment, those cells can continue changing until they become cancerous. This process is slow, typically taking many years, which is exactly why routine screening catches problems early.
HPV isn’t the only explanation, though. Inflammation from a yeast infection, bacterial vaginosis, or a herpes outbreak can make cells look mildly abnormal. Hormonal changes, pregnancy, and even certain vaginal medications can do the same. These non-viral causes most often show up as ASC-US, the mildest result category.
What Happens After an Abnormal Result
Your next steps depend on the severity of the abnormality combined with your screening history, not just the result on its own. Current guidelines base follow-up recommendations on your overall risk of having significant precancerous changes, which factors in both your current results and any previous test history.
For minor abnormalities with a low risk profile, such as ASC-US or LSIL in someone who recently had a normal screening, the typical approach is repeat testing in one year. An HPV test may be done on the same sample that produced your Pap result, and if that comes back negative, watchful waiting is usually all that’s needed.
For higher-risk findings, including HSIL, AGC, or a positive test for HPV strains 16 or 18 (the two strains most strongly linked to cervical cancer), the next step is usually a colposcopy. If the risk of significant precancerous changes is very high, treatment can sometimes be offered right away without waiting for additional biopsy results.
What a Colposcopy Involves
A colposcopy is an in-office exam where your provider uses a magnifying instrument to get a close-up, well-lit view of your cervix. You lie back as you would for a regular pelvic exam, a speculum is placed, and a mild solution is applied to your cervix with a cotton swab. This solution highlights any abnormal areas so they’re easier to see. You may feel a slight burning sensation when it’s applied.
If your provider spots anything that looks concerning, they’ll take a small tissue sample (biopsy) from that area during the same visit. They may also collect cells from inside the cervical canal. Taking an over-the-counter pain reliever beforehand can help with discomfort. For 24 hours before the procedure, avoid using tampons, vaginal medications, douching, or having sex.
If no biopsy is needed, you’ll feel fine immediately afterward and may have light spotting for a couple of days. If a biopsy is taken, expect some pain and discomfort for a day or two, along with vaginal bleeding and a dark discharge that can last several days. You’ll need to avoid putting anything in the vagina (no sex, no tampons) for a short period while the biopsy site heals. Heavy bleeding (soaking more than one pad per hour), severe abdominal pain, fever, or chills are signs to call your provider right away.
How Precancerous Changes Are Treated
Not all abnormal cells need to be removed. Low-grade changes (sometimes called CIN 1 on a biopsy report) are generally monitored rather than treated, because they usually resolve as the body clears the HPV infection.
High-grade changes (CIN 2 or CIN 3) are a different story. The preferred treatment in the U.S. is an excisional procedure, which removes a thin layer of abnormal tissue from the surface of the cervix. The most common version uses a heated wire loop to precisely cut away the affected area. This serves a dual purpose: it removes the abnormal cells and provides a tissue sample that can be examined more thoroughly in a lab. Removing the tissue often resolves the problem entirely by eliminating the precancerous cells, though it doesn’t clear the HPV virus itself. In some cases, a repeat procedure is needed if abnormal cells aren’t completely removed or if they return later.
After treatment for high-grade changes, you’ll need continued follow-up screening every three years for at least 25 years. This extended surveillance period exists because the risk of recurrence, while small, persists long after treatment.
Non-Cancerous Causes Worth Knowing About
It’s worth repeating that many abnormal Pap results have nothing to do with HPV or precancer. An inflamed cervix can look red, irritated, or eroded, and that alone can produce a mildly abnormal reading. Common causes of cervical inflammation include bacterial infections, yeast infections, trichomonas, herpes outbreaks, hormonal fluctuations, and chemical irritation from certain medications. Pregnancy itself can cause cell changes that show up as ASC-US. In these situations, treating the underlying issue (or simply waiting for hormonal changes to stabilize) often leads to a normal result on the next screening.
How Often You Should Be Screened
Screening guidelines for people at average risk are straightforward. Between ages 21 and 29, a Pap test every three years is recommended, with no need for HPV co-testing. Starting at age 30 through 65, the preferred approach is an HPV test alone every five years, or a combined Pap plus HPV test every five years. If HPV testing isn’t available, a Pap test every three years is an alternative. People at average risk should not be screened more frequently than every three years. Starting at age 30, self-collected HPV testing is also considered an appropriate option.
These intervals apply to routine screening. If you’ve had an abnormal result, your follow-up schedule will be more frequent until your results stabilize, and your provider will tell you exactly when to come back based on your specific situation.