陰道鏡是一種可以將子宮頸放大4到30倍 的子宮頸檢查內視鏡，陰道鏡並不會伸入陰道內。其實子宮頸若只靠肉眼觀察有時是很難將它檢查清楚的，可是陰道鏡卻可以將小小的子宮頸放大到非常清楚的地 步，子宮頸上如果有子宮頸癌的細胞病變，或是有快要變成子宮頸癌的癌症前期細胞病變，都可以在陰道鏡下早期發現。當陰道窺鏡置入陰道時，檢查醫師同時也可 以透過鏡頭看到陰道，外陰部的病變。
Colposcopy is a procedure to closely examine your cervix, vagina and vulva for signs of disease. Colposcopy is usually done to look at the vagina and cervix when the result of a Pap test is abnormal. Most abnormal Pap tests are caused by viral infection, such as human papillomavirus (HPV) infection, or other types of infection, such as those caused by bacteria, fungi (yeast), or protozoa (Trichomonas). During colposcopy, your doctor uses a lighted magnifying device that looks like a pair of binoculars (colposcope). The colposcope allows your doctor to see problems that would be missed by the naked eyes. A camera can be attached to the colposcope to take pictures or videos of the vagina and cervix.