What Is Cervical Cancer?
A plain-language overview of cervical cancer, where it starts, its main types, and how it is found, based on National Cancer Institute resources.
Source: National Cancer Institute · NCI reviewed 2023-06-15 · Verified 2026-07-02
The 30-second version
Cervical cancer is cancer that starts in the cells of the cervix, the lower, narrow end of the uterus that connects to the vagina. It usually develops slowly over time. Before cancer appears, the cells go through changes called dysplasia. Long-lasting HPV infection causes almost all cervical cancers.
Key takeaways
- Cervical cancer starts in the cells of the cervix, the lower, narrow end of the uterus.
- It usually develops slowly, after cells go through changes called dysplasia.
- Most cervical cancers begin in the transformation zone, where the inner and outer parts of the cervix meet.
- The two main types are squamous cell carcinoma (up to 90%) and adenocarcinoma.
- Long-lasting HPV infection causes almost all cervical cancers.
- Screening for cervical cancer is an important part of routine health care for people with a cervix.
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The full explanation.
The simple version
Cervical cancer is cancer that starts in the cells of the cervix. The cervix is the lower, narrow end of the uterus (womb). The cervix connects the uterus to the vagina (birth canal).
Cervical cancer usually develops slowly over time. Before cancer appears, the cells of the cervix go through changes known as dysplasia, in which abnormal cells begin to appear in the cervical tissue. Over time, if not destroyed or removed, the abnormal cells may become cancer cells and start to grow and spread more deeply into the cervix and to surrounding areas.
In short: cervical cancer starts in the cervix and usually develops slowly, after abnormal cell changes.
The parts of the cervix
The cervix has two main parts:
- The ectocervix (also called exocervix) is the outer part of the cervix that can be seen during a gynecologic exam. It is covered with thin, flat cells called squamous cells.
- The endocervix is the inner part of the cervix. It forms a canal that connects the vagina to the uterus. It is covered with column-shaped glandular cells that make mucus.
The transformation zone (also called the squamocolumnar junction) is the border where the endocervix and ectocervix meet. Most cervical cancers begin in this area.
Types of cervical cancer
Cervical cancers are named after the type of cell where the cancer started. The two main types are:
- Squamous cell carcinoma. Most cervical cancers (up to 90%) are squamous cell carcinomas. These cancers develop from cells in the ectocervix (the outer part of the cervix).
- Adenocarcinoma. Cervical adenocarcinomas develop in the glandular cells of the endocervix (the inner part of the cervix).
Sometimes cervical cancer has features of both squamous cell carcinoma and adenocarcinoma. This is called mixed carcinoma or adenosquamous carcinoma. Very rarely, cancer develops in other cells in the cervix.
In short: most cervical cancers are squamous cell carcinomas, and the next most common type is adenocarcinoma.
What raises the risk, and finding it early
Long-lasting HPV infection causes almost all cervical cancers. HPV stands for human papillomavirus. Your healthcare team can explain HPV, other risk factors, and what you can do to lower your risk.
If you have a cervix, screening for cervical cancer is an important part of routine health care. Screening can find abnormal cell changes early. Many cervical cancer symptoms are also seen with other, less serious conditions.
Everyone's situation is different. Your care team is the best source of information about your own health and any next steps.
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What Is Cervical Cancer: the quick overview
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Coming soonWhat Is Cervical Cancer, explained simply
The core ideas with friendly animation and plain language.
Coming soonUnderstanding what is cervical cancer — full lesson
A deeper walkthrough covering the key takeaways and common questions.
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Suggested animation storyboard▾
- 1Open on a calm title card: "What Is Cervical Cancer?" with the Cancer Explained mark.
- 2Narrator reads the 30-second summary while a soft animated diagram builds on screen: "Cervical cancer is cancer that starts in the cells of the cervix, the lower, narrow end of the uterus that connects to the vagina. It usually develops slowly over time. Before cancer appears, the cells go through changes called dysplasia. Long-lasting HPV infection causes almost all cervical cancers."
- 3Scene 2: illustrate the idea — "Cervical cancer starts in the cells of the cervix, the lower, narrow end of the uterus."
- 4Scene 3: illustrate the idea — "It usually develops slowly, after cells go through changes called dysplasia."
- 5Scene 4: illustrate the idea — "Most cervical cancers begin in the transformation zone, where the inner and outer parts of the cervix meet."
- 6Close on a reminder card: this is educational only; talk with your healthcare team, and a link to the NCI source.
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Quick knowledge check
According to this article, where does cervical cancer start?
Frequently asked questions
▸Where does cervical cancer start?
Cervical cancer starts in the cells of the cervix. The cervix is the lower, narrow end of the uterus (womb) that connects the uterus to the vagina. Most cervical cancers begin in an area called the transformation zone, where the inner and outer parts of the cervix meet.
▸How does cervical cancer develop?
Cervical cancer usually develops slowly over time. Before cancer appears, the cells of the cervix go through changes known as dysplasia, in which abnormal cells appear in the cervical tissue. Over time, if these abnormal cells are not destroyed or removed, they may become cancer cells and grow and spread more deeply into the cervix and surrounding areas.
▸What are the main types of cervical cancer?
The two main types are squamous cell carcinoma and adenocarcinoma. Up to 90% of cervical cancers are squamous cell carcinomas, which develop from cells in the outer part of the cervix. Adenocarcinomas develop in the glandular cells of the inner part of the cervix.
▸What causes almost all cervical cancers?
Long-lasting infection with HPV (human papillomavirus) causes almost all cervical cancers. Your healthcare team can explain HPV, other risk factors, and steps that may lower your risk.
▸Why is cervical cancer screening important?
If you have a cervix, screening for cervical cancer is an important part of routine health care. Screening can find abnormal cell changes early. Your healthcare team can explain when to get screened and what to expect.
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Questions to ask your healthcare team
Consider bringing these questions to your next appointment.
- What type of cervical cancer do I have, and where did it start?
- What do my HPV or Pap test results mean?
- When should I be screened for cervical cancer, and how often?
- What tests do I need to learn more about my cervical cancer?
- What are my treatment options, and what are the possible side effects?
- Where can I find reliable information and support?
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