The cervix forms a canal at the lower part of the uterus. The cervix opens into the vagina, or birth canal, which leads to the outside of the body.

Most cervical cancers start in the cells of the external lining of the cervix. Without treatment, this cancer can reach the small blood vessels and lymph vessels in the cervix. From there, it spreads to the rest of the body.

All of these put women at greater risk of developing cervical cancer. Women who smoke are about twice as likely as nonsmokers to get cervical cancer. HPV is a virus that causes genital warts. It is also the main cause of cervical cancer. Women with HPV or whose partners have HPV have a higher risk for cervical cancer. Sexual history is another important risk factor for cervical cancer. A woman or man with many sexual partners is more at risk for picking up a sexually transmitted virus like HPV. Women are also at greater risk for cervical cancer if they have many sexual partners, or if their male partners have had many sexual partners. The virus that causes AIDS damages the body's immune system and puts women more at risk for HPV infections. These may increase the risk for cervical cancer.

That's why it's important for a woman to have regular tests for cervical cancer. If all women had regular pelvic exams and Pap tests, most invasive cervical cancers could be prevented, according to the NCI. An effective way to prevent HPV infection is to get vaccinated against the virus. The vaccine is used to prevent, not treat, an HPV infection, the ACS says. To be most effective, the HPV vaccine should be given before a person begins having sexual intercourse.

Usually, by the time symptoms develop, the cancer has already become advanced. Abnormal vaginal bleeding, pain in the pelvic area, or loss of appetite may mean the cancer has reached nearby tissue.

The Pap test looks for any changes in the cells of the cervix. The test can see if you have changes that may be caused by an infection. It can also find abnormal cells that may progress to cancer. It can find cervical cancer, too. The Pap test takes only a few minutes. Your healthcare provider will put an instrument called a speculum into your vagina. He or she will use a brush or swab to take a few cells from the cervix. For most women, the test is painless, although some feel discomfort. The cells are checked in a lab to see if they are healthy. A pelvic exam is usually done at the same time as the Pap test, and an HPV test may also be done at the same time. In a pelvic exam, a healthcare provider checks the uterus and ovaries, too.

All women should start cervical cancer screening at age 21. Once a woman begins having a Pap test, she should continue to get one regularly, based on her healthcare provider's recommendations. Women who are 30 or older can get HPV tests along with their Pap tests. Women over age 65 who have had regular screening with normal results should not be screened for cervical cancer. Once screening is stopped, it should not be started again, according to the ACS.

Cervical cancer is more common in women who don't have regular Pap tests. Cervical cancer, or conditions that will eventually become cervical cancer, are more likely to be found early when a woman regularly gets a Pap test. The Pap test helps doctors find abnormal cells. Removing or killing the abnormal cells usually prevents cervical cancer.