The short answer
A positive result means one of these two high-risk HPV types was found in the sample. NCI says most HPV infections clear within a year or two. Cancer only becomes a risk when a high-risk infection persists for many years without being found and treated.
NCI lists 12 high-risk HPV types, and says 16 and 18 cause most HPV-related cancers.
Most HPV infections are cleared by the immune system within a year or two, NCI says.
Cancer risk comes from persistence over many years, not from the presence of the virus today.
A positive result after years of negatives is not necessarily a new infection; NCI says an old one can become active again.
Choose how you want to understand this
The full explanation.
What the test looked for, and what it found
An HPV test checks cervical cells for high-risk HPV types. NCI describes the two possible answers in plain terms. A negative result means high-risk HPV was not found. A positive result means it was.
Some tests go further and name which type. That is where 16 and 18 come from.
So your result says one thing: this virus is present in this sample now. It is a statement about today, not about the future.
Why these two types are named when the others are not
NCI lists 12 high-risk HPV types: 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58 and 59.
Then it separates two of them out. HPV 16 and HPV 18 are responsible for most HPV-related cancers.
NCI also names them when explaining why some infections last. Among the factors that increase the chance an infection will persist and lead to precancerous cells, it lists having a very aggressive HPV type, particularly HPV 16 or HPV 18. The others it names are smoking, a weakened immune system, HIV, and medicines that suppress immunity.
That is the reason your report singled out a number.
Positive means present, not permanent
This is the part that gets lost in the panic of reading the result.
NCI says most HPV infections go away on their own without causing cancer. The immune system usually controls them, and clears them within a year or two.
NCI also notes that infection with high-risk HPV causes no symptoms. Nothing about how you feel tells you whether an infection is clearing or staying.
HPV is also extremely common. NCI says around half of new infections are with a high-risk type.
The route from infection to cancer runs through years
NCI sets out the sequence carefully, and every step matters.
A high-risk infection that persists for many years can lead to cell changes. Those changes, if untreated, may get worse over time and become precancerous, and then cancerous.
Three conditions sit in that sentence. The infection has to persist. Many years have to pass. And the changes have to go untreated.
Screening exists to break the chain at the third step. NCI says routine screening with an HPV test or Pap test can prevent most cervical cancer, by finding and removing precancerous cells before they develop into cancer. It adds that cervical cancer is most common in women who are rarely or never screened.
A positive after years of negatives
NCI answers this one directly, and the answer is reassuring in an unusual way.
Sometimes, after several negative tests, a result comes back positive. NCI says this is not necessarily a sign of a new infection, because an HPV infection can become active again after many years. It compares this to chickenpox, which can reactivate later in life as shingles.
NCI is also honest about the limit of current knowledge. Researchers do not know whether a reactivated infection carries the same risk of cell changes or cancer as a new one.
What follow-up actually depends on
There is no single answer that applies to everyone with a positive 16 or 18 result, and NCI explains why.
Updated guidelines take a tailored approach. Alongside your current screening result, your clinician considers your previous screening results, any previous treatment for precancerous changes, and personal factors such as your age.
Based on that individual risk, NCI lists three possible paths:
- a repeat HPV test or HPV and Pap cotest in 1 or 3 years.
- a colposcopy with a biopsy.
- treatment for high-grade cervical cell changes.
NCI describes colposcopy as looking at the cervix with a lighted magnifying instrument, usually with a biopsy so the tissue can be checked under a microscope. It is a look, not a treatment.
The other cancers linked to these types
High-risk HPV is not only a cervical issue, and the numbers NCI publishes vary widely by site.
NCI says virtually all cervical cancer is caused by HPV. It attributes over 90% of anal cancer, 75% of vaginal cancer, 70% of oropharyngeal cancer, 69% of vulvar cancer, and 63% of penile cancer to HPV.
Those figures describe cancers that have already occurred. They are not the chance that any infection will become one.
HPV and Cancer covers the virus more broadly, Cervical Cancer Screening explains the testing schedule, and Colposcopy covers the procedure itself.
Sources
Words to know
Tap any term to see what it means.
Common questions
Does HPV 16 or 18 positive mean I have cancer?
No. The test reports that the virus is present in the sample now. NCI says infection with high-risk HPV does not cause symptoms, and that most infections are cleared by the immune system within a year or two. Cancer risk comes from an infection that persists for many years.
Why do these two types get named when the others do not?
Because they carry more risk. NCI lists 12 high-risk types, and says 16 and 18 cause most HPV-related cancers. It also names having a very aggressive type, particularly HPV 16 or 18, as a factor that makes an infection more likely to last and to lead to precancerous cells.
I have had negative tests for years. How is this positive?
NCI addresses this directly. A positive result after several negatives is not necessarily a sign of a new infection, because an HPV infection can become active again after many years. NCI adds that researchers do not know whether a reactivated infection carries the same risk as a new one.
Does this mean I need a colposcopy?
It may. NCI says follow-up is now based on your individual risk, taking in your current result, your previous screening results, any previous treatment and your age. The options it lists are a repeat test in 1 or 3 years, a colposcopy with biopsy, or treatment for high-grade changes.
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Sources last checked: 2026-08-09 what this meansLast updated: 2026-08-09Next planned review: 2027-08-09
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How this page was created
Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes. We do not employ clinicians and do not intend to — our work is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status: Source checked — This page was written with AI assistance and checked line by line against the sources listed on it. That confirms the sources support what the page says. It is not a medical review, and it does not confirm the page is complete or right for your situation.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
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