A risk factor  is anything that increases a person's chance of developing cancer. Although risk factors often influence the development of cancer, most do not directly cause cancer. Some people with several risk factors never develop cancer, while others with no known risk factors do. However, knowing your risk factors and talking about them with your doctor may help you make more informed lifestyle and health care choices.
The following factors may raise a woman's risk of developing cervical cancer:
Human papillomavirus (HPV) infection. The most important risk factor for cervical cancer is infection with HPV. This virus is most commonly passed from person to person during sexual activity. There are different types, or strains, of HPV, and some strains are more strongly associated with certain types of cancers. HPV vaccines protect against certain strains of the virus. Learn more about HPV and cancer .
Immune system deficiency. Women with lowered immune systems have a higher risk of developing cervical cancer. A lowered immune system can be caused by immune suppression from corticosteroid medications, organ transplantation, treatments for other types of cancer, or from the human immunodeficiency virus (HIV), the virus that causes acquired immune deficiency syndrome (AIDS). When a woman has HIV, her immune system is less able to fight off early cancer.
Herpes. Women who have genital herpes have a higher risk of developing cervical cancer.
Smoking. Women who smoke are about twice as likely to develop cervical cancer as women who do not smoke.
Age. Girls younger than 15 rarely develop cervical cancer. The risk goes up between the late teens and mid-30s. Women over 40 remain at risk and need to continue having regular Pap test screenings (see below).
Race. Cervical cancer is more common among black women, Hispanic women, and American Indian women.
Oral contraceptives. Some research studies suggest that oral contraceptives (birth control pills) may be associated with an increase in the risk of cervical cancer. However, more research is needed to understand how oral contraceptive use and the development of cervical cancer are connected.
Exposure to diethylstilbestrol (DES). Women whose mothers were given this drug during pregnancy to prevent miscarriage have an increased risk of cervical cancer. DES was given for this purpose from about 1940 to 1970. Women exposed to DES should have an annual pelvic examination that includes a cervical Pap test  as well as a four-quadrant Pap test, in which samples of cells are taken from all sides of the vagina to check for abnormal cells.