The cervical smear is a screening test designed to detect pre-cancerous changes in the cervix (neck of the womb). Pre-cancerous changes called cervical intra-epithelial neoplasia (CIN) are common in all age groups and cause no symptoms. This means that women will not be aware of CIN unless they have a screening test. The first stage in cervical screening is either a smear test or Liquid Based Cytology (LBC).

There is always the potential that pre-cancerous changes might go on to become actual cancer of the cervix. It is not certain how long it takes for the abnormal cells to develop into cancer. Early detection and treatment can prevent 75 per cent of cancers developing. If preventive measures are not taken, cancer does develop in up to 50 per cent of cases, although this might take several years to happen.

The Pap smear is performed as part of a gynecological exam. You will lie on a table and place your feet in stirrups to position your pelvis for examination. A speculum (an instrument used to open the walls of the vaginal canal to see the interior) will be inserted into your vagina and opened slightly. A sample of surface cells is taken from the cervix with a small flat wooden spatula or a small brush. The specimen is placed on a small glass slide, fixed, stained and sent away to a laboratory to be examined under a microscope. The pathologist or cytologist will then classify the smear test into either normal, inflammation, mild, moderate or severely dysplasia, or neoplasia (cancer).

A cervical biopsy (colposcopy) is usually performed when a pap smear indicates significant abnormalities, or when an abnormal area is seen on the cervix during a routine pelvic examination. When a positive pap smear shows minor cell changes or abnormalities, a biopsy probably will not be done immediately, unless there is a reason to believe you may be in a high-risk category. For minor cell changes, it is usually recommended that a repeat pap smear be done in 6 months.

Women should not wait until they notice gynaecological symptoms before having an examination. All women between the ages of 25 and 64 should do cervical screening test every three to five years. We can use the interval of screening done by NHS Cervical Screening Programme below as a guidance.

The intervals are:
First invitation at 25 years age group ; once in three years at 25-49 years age group ; once in five years at 50-64 years age group ; and for > 65 years age group, only screen those who have not been screened since age 50 or have had recent abnormal tests.