Common Changes in Cervical Cells
Cell Changes Caused by HPV Are a Special Concern
Other Risk Factors for Cervical Cancer

The cervix is the narrow, lower part of the uterus (where the baby grows when a woman is pregnant). During a pelvic exam, the doctor or nurse practitioner can see the cervix at the upper end of the vagina.

The cervix has an opening to the endocervical canal. This opening lets blood flow from the uterus into the vagina during a woman's menstrual period. During childbirth, the cervix opens much wider to let the baby pass through.

The surface lining of the cervix is made up of two different types of cells:

• Tall cells, called glandular cells (or columnar cells) toward the top of the endocervical canal (above the cervix). They make mucus, which helps guard the entrance to the uterus.

• Thin, flat cells, called squamous epithelial cells (or squamous cells). Arranged in layers, they protect the tissues underneath them.

Pap tests can help health care providers find changes in these cells.

Normal cervical cells	Normal and precancerous mix	Precancerous cervical cells

Common Changes in Cervical Cells

Cervical cells can go through many types of changes that are not cancer. Many times these changes will go away on their own. These changes can be caused by:

• Inflammation (redness and swelling)
• An infection (bacterial, viral, or yeast)
• Growths such as benign polyps or cysts
• Changes in hormones from pregnancy or menopause

These cell changes are very common and are not related to cancer. But they sometimes make these cells look like abnormal cells. So your health care provider may suggest that you repeat your Pap test or have other follow-up tests to be certain you don't have any cell changes. (See the tables beginning at Table 1 ¹ for more information.)

Cell Changes Caused by HPV Are a Special Concern

Some cell changes are a sign of a certain viral infection called HPV (human papillomavirus). In most women, HPV infections go away on their own. Sometimes, the cells infected with HPV will become precancerous. These precancerous cells can become cervical cancer (called invasive cancer of the cervix). They can grow and spread, invading nearby tissues and possibly spreading throughout the body. An HPV test, which is done much like a Pap test, can detect the virus in cervical cells.

Other Risk Factors for Cervical Cancer

HPV is the most important cause of and risk factor for cervical cancer. But studies have shown that other factors may act together with HPV to increase your risk of developing cervical cancer. These factors include cigarette smoking and having given birth to many children. Also, if you have a weak immune system, you may be at higher risk because your body may not be able to clear up HPV on its own. For example, if you take medicine to block your body's immune response or if you have HIV, you may be at higher risk.

Glossary Terms

Not normal. An abnormal lesion or growth may be cancer, premalignant (likely to become cancer), or benign (not cancer).

A large group of single-cell microorganisms. Some cause infections and disease in animals and humans. The singular of bacteria is bacterium.

A sac or capsule in the body. It may be filled with fluid or other material.

The cause of acquired immunodeficiency syndrome (AIDS). Also called human immunodeficiency virus.

One of many chemicals made by glands in the body. Hormones circulate in the bloodstream and control the actions of certain cells or organs. Some hormones can also be made in the laboratory.

A type of virus that can cause abnormal tissue growth (for example, warts) and other changes to cells. Infection for a long time with certain types of HPV may cause cervical cancer. HPV may also play a role in some other types of cancer. Also called human papillomavirus.

Invasion and multiplication of germs in the body. Infections can occur in any part of the body and can spread throughout the body. The germs may be bacteria, viruses, yeast, or fungi. They can cause a fever and other problems, depending on where the infection occurs. When the body’s natural defense system is strong, it can often fight the germs and prevent infection. Some cancer treatments can weaken the natural defense system.

Cancer that has spread from the surface of the cervix to tissue deeper in the cervix or to other parts of the body.

A growth that protrudes from a mucous membrane.

A term used to describe a condition that may (or is likely to) become cancer. Also called premalignant.

Something that increases the chance of developing a disease. Some examples of risk factors for cancer are age, a family history of certain cancers, use of tobacco products, being exposed to radiation or certain chemicals, infection with certain viruses or bacteria, and certain genetic changes.

The small, hollow, pear-shaped organ in a woman's pelvis. This is the organ in which a fetus develops. Also called womb.

The muscular canal extending from the uterus to the exterior of the body. Also called birth canal.

Having to do with a virus.