Grading CIN

CIN is graded depending on how deep the cell changes go into the surface of the cervix:

  • CIN 1 – this is when one-third of the thickness of the surface layer of the cervix is affected.
  • CIN 2 – this is when two-thirds of the thickness of the surface layer of the cervix is affected.
  • CIN 3 – this is when the full thickness of the surface layer of the cervix is affected.

Knowing the grade of your CIN helps your colposcopist plan the best treatment for you.

With all three grades of CIN, often only a small part of the cervix is affected by abnormal changes.

CIN 3 is also known as carcinoma-in-situ. Although this may sound like cancer, CIN 3 is not cervical cancer. Cancer has developed when the deeper layers of the cervix are affected by abnormal cells. However, it's important that if CIN 3 is picked up during screening tests, plans are made to treat it as soon as possible.

Back to Cervical screening

The cervix

The cervix is the lower part of the womb (uterus). It’s often called the neck of the womb.

Diagnosing CIN

A colposcopy is used to confirm whether you have cervical intra-epithelial neoplasia (CIN) and how severe it might be.

Treating CIN

If you have been diagnosed with CIN, you may have treatment to remove the abnormal cells. There are different types of treatment.

After treatment for CIN

Most women feel fine after treatment for CIN but some may feel unwell for a few hours. You will be referred for regular screening tests.