Cervical dysplasia is the presence of abnormal cells in the cervix. Cases are classified as mild, moderate or severe depending on the extent of abnormal cell growth.

Although cervical dysplasia is not cancer, it is a precancerous condition, which means it may develop into cancer if left untreated. Cervical dysplasia is also known as cervical intraepithelial neoplasia (CIN) or squamous intraepithelial lesion (SIL).

Although the precise cause of cervical dysplasia is not known, it has been linked to exposure to the human papillomavirus (HPV). HPV is a group of more than 100 viruses, some of which can cause cells on the cervix to behave abnormally. Among the risk factors for HPV infection are having multiple sexual partners, a history of other sexually transmitted diseases and cigarette smoking.

Cervical dysplasia usually has no symptoms, but a woman may experience genital warts, abnormal bleeding and bleeding or spotting after sexual intercourse.

Cervical dysplasia is usually detected during a routine gynecological examination with a screening test called a Pap smear. During this test, a physician scrapes cells from the surface of the cervix and sends them to a laboratory where they are examined under a microscope to detect the presence of abnormal cells. If abnormal cells are identified on the Pap smear, a colposcopy (an examination of the cervix using an instrument with a lighted magnifying glass) may be performed. A biopsy of tissue samples also may be completed to determine whether abnormal cells are cancerous.