Cold coagulation

Information for patients

Obstetrics and gynaecology

Why have I been offered cold coagulation?

The biopsy taken at your recent visit to the colposcopy clinic has confirmed the presence of a pre-cancerous change called ‘cervical intra-epithelial neoplasia’, or CIN. Cold coagulation is an effective treatment for CIN.

Cold coagulation may also be used to treat delicate soft cells on the cervix which bleed easily when touched (an ectropian). The procedure cauterises (burns) the soft cells so that they become hardened and less likely to bleed when touched.

What is involved?

  • Firstly a colposcopy will be performed to identify the abnormal area.

  • Cold coagulation can be performed with or without local anaesthetic. The colposcopist will advise you as to which would be the most appropriate for you. If you do have a local anaesthetic, the colposcopist will inject this into your cervix. This means you are awake, but the area that needs treatment is numb (you cannot feel it). The injection might sting for a short time and you may be aware of your heart beating faster. This feeling should pass within a couple of minutes.

  • Although called cold coagulation, the treatment actually uses heat to destroy abnormal cells. A heated probe is applied the abnormal area for 20 seconds. Occasionally more than one application will be recommended.

  • Whilst the treatment itself takes just a few minutes, afterwards you will be taken to recovery to rest for at least 20 minutes, so please allow an hour in total for your appointment.

  • You are welcome to have someone with you for support.

What are the benefits?

Cold coagulation is a simple and safe technique which gives excellent results. It is successful in over 9 in 10 (90%) cases, meaning no further treatment is needed.

What are the risks?

  • Bleeding: There is a small risk of heavy bleeding (for example soaking through a sanitary pad every hour).

  • Infection: There is a small risk of infection. Symptoms include painful cramps, a high temperature and/or smelly discharge.

  • Cervical stenosis: There is a very small risk that the opening of the cervix will become narrowed due to scarring. This can cause painful periods, difficulty conceiving or the cervix not to open well during labour. This risk increases if you have been through menopause or have had a treatment on your cervix previously.

  • Burn: There is a very small risk of a burn to the vagina.

What can I expect afterwards?

You may experience some or none of the following:

  • Some mild period-type pain for a few days.

  • A very watery, blood-stained discharge. This could last up to 4 weeks.

  • You may feel light headed/faint after your treatment. If you have a tendency to faint, then we advise you to arrange for a friend or relative to transport you home afterwards.

  • If you have periods, the next one may be slightly heavier/lighter or out-of-sync with your regular cycle. It should soon settle into its usual pattern.

If you are concerned that you are bleeding too heavily or have an infection please contact Greenoaks or your GP during weekday working hours, or Ward B11 out of hours on 01709 424349.


Until all bleeding/discharge has stopped it is recommended to avoid:

  • penetrative vaginal sex - including fingers, tongues and other objects

  • tampons or menstrual cups - you can use pads instead

  • heavy exercise that causes you to sweat

  • swimming and hot tubs

  • baths - you can shower as normal

Practical advice

  • Please make sure you eat and drink something before your appointment.

  • You will be safe to drive following cold coagulation under local anaesthetic, unless advised otherwise by the colposcopist.

  • You can return to work as soon as you feel able. l If you have a contraceptive coil, it may be left in place. The heat from the treatment will not affect its use.

  • Please advise your colposcopist of any upcoming holidays, as it may affect your care plan. We may need to delay cold coagulation until after your return home, because of the risk of bleeding and infection. In addition, some travel insurance companies may not provide you with cover immediately following cold coagulation.

  • If you are pregnant then we prefer not to do any treatment on your cervix. We will re-arrange a date, usually three months after your baby is born. However, we may suggest a colposcopy during your pregnancy which is not harmful to your baby.

  • If you are having your period we can still carry out cold coagulation provided that your bleeding is light. Please call the Colposcopy Office or Greenoaks for advice before cancelling your appointment.

Results and follow up

We will recommend a cervical screening (smear) test called a Test of Cure. This takes place 6 months after cold coagulation.

How to contact us

Colposcopy Secretaries

01709 424300
Monday to Friday, 9am to 4pm

Health Advice

01709 427641
Monday to Friday, 9am to 4pm

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  • Page last reviewed: 31 May 2024
  • Next review due: 31 May 2025