The cervix has two types of epithelium: kolumnair and skwamosa associated with squamous-columnar junction, the part between the outer and inner lips of the cervix, may alter the cell to abnormalities.
Pre-cancerous period (after the cell turns to abnormal) is a period of three stages of cell changes called cervical intraepithelial neoplasia (CIN), namely CIN 1, CIN 2, and CIN 3.
After CIN 3, the abnormal cells become very thick and eventually become cancerous.
Changes in CIN 1 to cancer require 3 - 10 years so early detection is very important.
