HPV types: low-risk and high-risk types (16 and 18)
HPV is not a single virus but a family with more than 200 types. The most important distinction is this: low-risk types (especially 6 and 11) mostly cause genital warts; high-risk types (especially 16 and 18) are linked to some cancers if they persist. Which type shows up on your test result directly affects follow-up decisions. Knowing your type is not a reason to panic; it is the key to proper follow-up.
If you have seen a type number on your HPV test (for example HPV 16) or come across the phrase "high-risk HPV", this article is for you. Let's sort the types out in plain language and look, step by step, at what each one means and why some types get extra attention. If you like, you can first read our article What is HPV?
How many types of HPV are there?
HPV is a family of more than 200 related viruses. Each one is given a number (HPV 6, HPV 16, HPV 18…). Not all of these types cause disease; most are harmless. What matters in clinical practice is which risk group a type belongs to:
| Group | Key types | What it means |
|---|---|---|
| Low-risk | HPV 6, 11 | Mostly linked to genital warts; not expected to cause cancer. |
| High-risk | HPV 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59 | If persistent, linked to some cancers, above all cervical cancer. |
| Group covered by the test | 14 high-risk types (including 66 and 68) | HPV-DNA tests usually look for these 14 types together. |
| Vaccine coverage (9-valent) | 6, 11, 16, 18, 31, 33, 45, 52, 58 | The current vaccine targets the important types linked to both warts and cancer. |
Low-risk types (6 and 11)
As the name suggests, low-risk types carry a low risk of cancer. The best known are HPV 6 and HPV 11:
- These two types cause the vast majority of genital warts (condylomas).
- Warts are benign; they can be bothersome, but they are not expected to turn into cancer.
- Still, it is right to see a doctor for treatment and follow-up.
High-risk types (16, 18, 31…)
High-risk types are those that, once they persist, can lead to cell changes and, over time, to some cancers. The main known high-risk types are 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58 and 59; HPV-DNA test panels also add 66 and 68, so a total of 14 high-risk types are tested.
Important: Finding a high-risk type does not mean "I have cancer". Most of these types also clear on their own. Risk becomes a concern when the infection persists for years and is not monitored.
Why do HPV 16 and 18 matter in particular?
Among the high-risk types, HPV 16 and HPV 18 have a special place:
A large share of cervical cancers are linked to HPV 16 and 18; that is why tests often report these two types separately.
- HPV 16: Stands out as the highest-risk type.
- HPV 18: Needs extra attention because of its link to cancers of the glandular cells of the cervix (adenocarcinoma).
So if your result says "16 positive" or "18 positive", your doctor will usually discuss whether a closer evaluation (for example, a colposcopy) is needed. This is not a reason to panic; it is appropriate caution.
"14 high-risk types" and genotyping
HPV-DNA tests usually do not check each type one by one; they look for 14 high-risk types together. The result can come in two forms:
- Positive / negative (pooled): Whether any of these 14 types is present or not.
- Genotyping: A result that tells you "which type", with 16 and 18 in particular reported separately.
The phrase "14 high-risk types tested" is not bad news; it describes the scope of the test. What matters is whether the result is positive or negative and, if positive, which type it is.
Which types does the vaccine cover?
The current HPV vaccine (9-valent) targets the most important types, both those that cause warts and those linked to cancer: 6, 11, 16, 18, 31, 33, 45, 52 and 58. In other words, the vaccine aims to protect not against a single type but against a group of the types that most often cause problems.
The vaccine does not treat an existing infection; it works best before exposure to the types it covers. Eligibility depends on age and individual circumstances, and is assessed with a doctor.
What does the type number on my result mean?
When reading your result, note these three questions. They make the conversation with your doctor easier:
- Is the result positive or negative?
- If positive, which type is it (especially, is it 16/18)?
- Do you have a Pap test result from the same period?
A type number is not a diagnosis on its own. It is assessed together with your age, your Pap test result and your previous tests. Go through this assessment with your doctor.
When should you see a doctor?
These are usually not emergencies, but they should be evaluated in good time:
- your HPV test is positive for a high-risk type (especially 16/18),
- your Pap test result shows an abnormality,
- you notice a new wart or change in the genital area,
- you are of screening age and have not had a check-up for a long time.
Knowing your type empowers you throughout the process. It helps you ask the right questions and keep up with follow-up.
Frequently asked questions
I tested positive for HPV 16. Do I have cancer?
No. A positive HPV 16 result only shows that this high-risk type is present; on its own, it is not a cancer diagnosis. Most high-risk infections also clear on their own. Your doctor will assess, together with your Pap test result and your age, whether closer follow-up is needed.
Why does HPV 18 matter in particular?
HPV 18 is followed closely, together with 16, because of its link to cancers of the glandular cells of the cervix (adenocarcinoma). That is why many tests report 16 and 18 separately.
Is low-risk HPV (6, 11) dangerous?
Low-risk types are mostly linked to genital warts and are not expected to cause cancer. Warts are benign; still, it is right to see a doctor for treatment and follow-up.
What does "14 high-risk types tested" mean?
HPV-DNA tests usually look for 14 high-risk types together. This phrase describes the scope of the test; it does not mean a bad result. What matters is whether the result is positive or negative and, if positive, which type it is.
Can I have more than one HPV type at the same time?
Yes, more than one type can be present at the same time. Your doctor decides on follow-up based on an overall assessment; on its own, this does not mean a worse situation.
Can types I was vaccinated against still show up?
The vaccine gives the strongest protection before exposure to the types it covers. A type acquired before vaccination can still be found, and the vaccine does not cover all types. That is why screening continues for vaccinated people too.
Does high-risk HPV always cause cancer?
No. Most high-risk infections also clear on their own. Cancer risk becomes a concern when the infection persists for years and is not monitored; regular screening catches this process early.
Sources
- Republic of Türkiye Ministry of Health, General Directorate of Public Health — Cervical cancer screening program and HPV-DNA screening information.
- World Health Organization (WHO) — Information resources on human papillomavirus (HPV) and cervical cancer.
- Centers for Disease Control and Prevention (CDC) — Information on HPV types, vaccination and screening.
- National Cancer Institute (NCI) — HPV types and their link to cancer.
Note: This content was written independently, based on current scientific information published by the institutions above; it is not a direct copy of any text.
This article is for general information only; it is not a diagnosis or treatment recommendation and does not replace a medical examination. Please consult your doctor about your own situation. The content reflects scientific knowledge as of the update date above.