Cervical cancer starts in the cells lining the cervix, the narrow opening between the uterus and vagina

Cervical cancer begins when cells in the cervix grow abnormally and become cancerous. Most cervical cancers are caused by infection with human papillomavirus (HPV), a virus spread through sexual contact. Not everyone infected with HPV develops cervical cancer—the immune system clears the virus in most people. But in some cases, the infection persists and causes changes in cervical cells that can turn into cancer over time.

The cervix is the lower part of the uterus. It connects the main body of the uterus to the vagina. Cancer can develop in two types of cells that line the cervix: squamous cells (which cover most of the cervix) or glandular cells (which produce mucus). Squamous cell carcinoma is more common, accounting for about 80 to 90 percent of cervical cancers.

Cervical cancer usually develops slowly. Abnormal cells may exist for years before becoming cancerous. This slow progression is why regular screening tests can catch changes early, before cancer forms.

Key Takeaways

  • Most cervical cancers are caused by persistent infection with HPV, a virus spread through sexual contact.
  • Cervical cancer develops slowly from abnormal cells, often over many years, which makes early detection through screening possible.
  • Risk factors include smoking, a weakened immune system, long-term use of birth control, and having multiple sexual partners.
  • Early-stage cervical cancer often has no symptoms, which is why screening tests are the main way to find it.
  • The HPV vaccine can prevent the types of HPV most likely to cause cervical cancer if given before infection occurs.

How HPV infection leads to cervical cancer

HPV is a common virus—most sexually active people are exposed to it at some point. There are more than 100 types of HPV, but only a few cause cervical cancer. Types 16 and 18 are responsible for about 70 percent of cervical cancers. When HPV infects cervical cells, it can cause them to change in ways that are visible under a microscope.

In most people, the immune system fights off HPV within one to two years. But in some people, the virus persists. Over time, persistent infection can cause cells to develop precancerous changes called dysplasia or cervical intraepithelial neoplasia (CIN). These changes do not mean cancer is present, but they signal that cancer could develop if the cells are not monitored or treated.

If precancerous changes are not found and treated, they may progress to invasive cervical cancer, where cancer cells break through the surface of the cervix and grow into deeper tissue. This progression typically takes years, which is why screening every three to five years catches most problems before they become serious.

Risk factors that increase the chance of cervical cancer

While HPV infection is the main cause, other factors make some people more likely to develop cervical cancer. Smoking weakens the immune system's ability to fight HPV infection and may directly damage cervical cells. People who smoke are roughly twice as likely to develop cervical cancer as non-smokers.

A weakened immune system from HIV, organ transplant, or immunosuppressive medications makes it harder for the body to clear HPV. Long-term use of hormonal birth control (pills, patches, or rings) for five or more years is associated with increased risk, though the risk drops after stopping. Having multiple sexual partners or a partner with multiple partners increases HPV exposure.

Age also matters. Cervical cancer is most common in people aged 35 to 44, though it can occur at any age after sexual activity begins. People who began sexual activity very young or had a first pregnancy before age 20 have higher risk. Socioeconomic factors also play a role—people with less access to screening and healthcare are diagnosed at later stages.

Early signs and symptoms

Early-stage cervical cancer often causes no symptoms at all. This is why screening is so important—it finds changes before a person feels sick. When symptoms do appear, they usually show up in more advanced stages.

Common symptoms include abnormal vaginal bleeding (between periods, after sex, or after menopause), unusual vaginal discharge that may be watery or bloody, pelvic pain, and pain during sex. Heavy vaginal bleeding or discharge with a foul odor can indicate more advanced disease. Some people also experience lower back pain or pain in the legs.

These symptoms can have other causes—infections, polyps, or hormonal changes—so having them does not mean cancer is present. But any unusual bleeding or discharge should be reported to a healthcare provider, who can examine you and run tests if needed.

How cervical cancer is found through screening

Screening tests look for HPV infection or precancerous cell changes before cancer develops. The Pap test (or Pap smear) collects cells from the cervix and checks them under a microscope for abnormalities. The HPV test detects the presence of high-risk HPV types. Some screening uses both tests together, which is more effective than either alone.

Screening guidelines vary by age and risk factors. Most organizations recommend that people with a cervix start screening at age 21 and continue every three years (Pap test alone) or every five years (HPV test alone or combined testing). Screening typically stops at age 65 or 70 if previous tests have been normal and the person is not at high risk.

If screening finds abnormal cells, the next step is usually a colposcopy, where a doctor uses a magnifying instrument to look closely at the cervix and may take a small tissue sample (biopsy) to check for cancer or precancerous changes. Most abnormal results do not mean cancer is present, but they do mean the cells need to be watched or treated.

Stages of cervical cancer

Cervical cancer is staged based on how far it has spread. Stage 1 means cancer is found only in the cervix. Stage 2 means it has spread beyond the cervix but not to the pelvic wall or lower vagina. Stage 3 means it has reached the pelvic wall, lower vagina, or nearby lymph nodes. Stage 4 means it has spread to the bladder, rectum, or distant organs like the lungs or liver.

Early-stage cervical cancer (stages 1 and 2) is often highly treatable. Treatment may include surgery to remove the cervix and uterus, radiation therapy, chemotherapy, or a combination. Advanced-stage cancer is more difficult to treat but treatment options still exist.

The stage at diagnosis makes a major difference in outcomes. People diagnosed with stage 1 cervical cancer have a five-year survival rate of about 90 percent or higher. This is why screening that catches precancerous changes or early cancer is so valuable.

Prevention through HPV vaccination

The HPV vaccine prevents infection with the types of HPV most likely to cause cervical cancer. It is most effective when given before a person becomes sexually active, ideally in the early teenage years. The vaccine is approved for people aged 9 to 45 and is recommended for all people in that age range who have not been vaccinated.

The vaccine does not treat existing HPV infection, so it works best as prevention. Even people who have been exposed to HPV may still benefit from vaccination against types they have not encountered. The vaccine is given as a series of shots over several months.

Vaccination does not replace screening. People who are vaccinated still need regular screening because the vaccine does not protect against all cancer-causing HPV types. But vaccination combined with screening offers the strongest protection against cervical cancer.

Frequently Asked Questions

Can you get cervical cancer without HPV?

Rarely. HPV causes about 99 percent of cervical cancers. The small percentage of cases not linked to HPV are usually adenocarcinomas (cancers of glandular cells) or cancers in people with a very weakened immune system. But HPV infection is so common that it is the primary risk factor to understand.

Does having HPV mean you will definitely get cervical cancer?

No. Most people who get HPV clear the infection on their own within a year or two. Only a small percentage of people with persistent HPV infection develop precancerous changes, and even fewer develop cancer. Regular screening catches changes early, before cancer forms.

Is cervical cancer hereditary?

Cervical cancer itself is not inherited, but some genetic factors may affect how well your immune system fights HPV infection. Family history of cervical cancer does not increase your personal risk the way it does for some other cancers. HPV exposure and screening history matter much more.

Can men get cervical cancer?

No, because men do not have a cervix. However, men can carry and spread HPV, and HPV can cause cancers in men, including cancers of the penis, anus, and throat. The HPV vaccine is recommended for men as well to prevent these cancers and reduce transmission.

What happens if cervical cancer is found at a very early stage?

Early-stage cervical cancer is highly treatable. Treatment may be as simple as removing the abnormal tissue during a procedure, or it may involve surgery to remove the cervix and uterus. Many people treated for early cervical cancer go on to live long, healthy lives. This is why screening is so important.